From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 20 Feb 2006 04:05:16 +0000 (+0000)
Subject: 1) Add flexible seeking support (including absolute) for memory block queues and... 
X-Git-Tag: v0.8~258
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=304449002cbc84fdcf235b5dfaec891278dd7085;p=platform%2Fupstream%2Fpulseaudio.git

1) Add flexible seeking support (including absolute) for memory block queues and playback streams
2) Add support to synchronize multiple playback streams
3) add two tests for 1) and 2)
4) s/PA_ERROR/PA_ERR/
5) s/PA_ERROR_OK/PA_OK/
6) update simple API to deal properly with new peek/drop recording API
7) add beginnings of proper validity checking on API calls in client libs (needs to be extended)
8) report playback buffer overflows/underflows to the client
9) move client side recording mcalign stuff into the memblockq
10) create typedefs for a bunch of API callback prototypes
11) simplify handling of HUP poll() events

Yes, i know, it's usually better to commit a lot of small patches instead of a
single big one. In this case however, this would have contradicted the other
rule: never commit broken or incomplete stuff.

*** This stuff needs a lot of additional testing! ***


git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@511 fefdeb5f-60dc-0310-8127-8f9354f1896f
---

diff --git a/src/Makefile.am b/src/Makefile.am
index f973dc4..4cf61f2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -180,7 +180,9 @@ noinst_PROGRAMS = \
 		pacat-simple \
 		parec-simple \
 		strlist-test \
-		voltest
+		voltest \
+		memblockq-test \
+		sync-playback
 
 if HAVE_SIGXCPU
 noinst_PROGRAMS += \
@@ -248,6 +250,24 @@ mainloop_test_glib12_CFLAGS = $(mainloop_test_CFLAGS) $(GLIB12_CFLAGS) -DGLIB_MA
 mainloop_test_glib12_LDADD = $(mainloop_test_LDADD) $(GLIB12_LIBS) libpolyp-mainloop-glib12-@PA_MAJORMINOR@.la
 mainloop_test_glib12_LDFLAGS = $(AM_LDFLAGS) $(BINLDFLAGS)
 
+memblockq_test_SOURCES = \
+	tests/memblockq-test.c \
+	polypcore/memblockq.c \
+	polypcore/log.c \
+	polypcore/memblock.c \
+	polypcore/xmalloc.c \
+	polypcore/util.c \
+	polypcore/mcalign.c \
+	polypcore/memchunk.c
+memblockq_test_CFLAGS = $(AM_CFLAGS)
+memblockq_test_LDADD = $(AM_LDADD)
+memblockq_test_LDFLAGS = $(AM_LDFLAGS) $(BINLDFLAGS)
+
+sync_playback_SOURCES = tests/sync-playback.c
+sync_playback_LDADD = $(AM_LDADD) libpolyp-@PA_MAJORMINOR@.la libpolyp-mainloop-@PA_MAJORMINOR@.la
+sync_playback_CFLAGS = $(AM_CFLAGS) 
+sync_playback_LDFLAGS = $(AM_LDFLAGS) $(BINLDFLAGS)
+
 ###################################
 #         Client library          #
 ###################################
diff --git a/src/modules/module-combine.c b/src/modules/module-combine.c
index aabb8f2..750eca6 100644
--- a/src/modules/module-combine.c
+++ b/src/modules/module-combine.c
@@ -144,7 +144,7 @@ static void request_memblock(struct userdata *u) {
         return;
 
     for (o = u->outputs; o; o = o->next)
-        pa_memblockq_push_align(o->memblockq, &chunk, 0);
+        pa_memblockq_push_align(o->memblockq, &chunk);
 
     pa_memblock_unref(chunk.memblock);
 }
@@ -212,7 +212,15 @@ static struct output *output_new(struct userdata *u, pa_sink *sink, int resample
     o->userdata = u;
     
     o->counter = 0;
-    o->memblockq = pa_memblockq_new(MEMBLOCKQ_MAXLENGTH, MEMBLOCKQ_MAXLENGTH, pa_frame_size(&u->sink->sample_spec), 0, 0, sink->core->memblock_stat);
+    o->memblockq = pa_memblockq_new(
+            0,
+            MEMBLOCKQ_MAXLENGTH,
+            MEMBLOCKQ_MAXLENGTH,
+            pa_frame_size(&u->sink->sample_spec),
+            1,
+            0,
+            NULL,
+            sink->core->memblock_stat);
 
     snprintf(t, sizeof(t), "%s: output #%u", u->sink->name, u->n_outputs+1);
     if (!(o->sink_input = pa_sink_input_new(sink, __FILE__, t, &u->sink->sample_spec, &u->sink->channel_map, 1, resample_method)))
diff --git a/src/modules/module-tunnel.c b/src/modules/module-tunnel.c
index 61b9bb3..6723658 100644
--- a/src/modules/module-tunnel.c
+++ b/src/modules/module-tunnel.c
@@ -214,7 +214,7 @@ static void send_bytes(struct userdata *u) {
             return;
         }
 
-        pa_pstream_send_memblock(u->pstream, u->channel, 0, &chunk);
+        pa_pstream_send_memblock(u->pstream, u->channel, 0, PA_SEEK_RELATIVE, &chunk);
         pa_memblock_unref(chunk.memblock);
 
         if (chunk.length > u->requested_bytes)
@@ -442,7 +442,7 @@ static void pstream_packet_callback(pa_pstream *p, pa_packet *packet, void *user
 }
 
 #ifndef TUNNEL_SINK
-static void pstream_memblock_callback(pa_pstream *p, uint32_t channel, uint32_t delta, const pa_memchunk *chunk, void *userdata) {
+static void pstream_memblock_callback(pa_pstream *p, uint32_t channel, int64_t offset, pa_seek_mode_t seek, const pa_memchunk *chunk, void *userdata) {
     struct userdata *u = userdata;
     assert(p && chunk && u);
 
diff --git a/src/polyp/context.c b/src/polyp/context.c
index 6b77856..eac5dd2 100644
--- a/src/polyp/context.c
+++ b/src/polyp/context.c
@@ -74,6 +74,8 @@
 
 static const pa_pdispatch_callback command_table[PA_COMMAND_MAX] = {
     [PA_COMMAND_REQUEST] = pa_command_request,
+    [PA_COMMAND_OVERFLOW] = pa_command_overflow_or_underflow,
+    [PA_COMMAND_UNDERFLOW] = pa_command_overflow_or_underflow,
     [PA_COMMAND_PLAYBACK_STREAM_KILLED] = pa_command_stream_killed,
     [PA_COMMAND_RECORD_STREAM_KILLED] = pa_command_stream_killed,
     [PA_COMMAND_SUBSCRIBE_EVENT] = pa_command_subscribe_event
@@ -109,9 +111,10 @@ pa_context *pa_context_new(pa_mainloop_api *mainloop, const char *name) {
     PA_LLIST_HEAD_INIT(pa_stream, c->streams);
     PA_LLIST_HEAD_INIT(pa_operation, c->operations);
     
-    c->error = PA_ERROR_OK;
+    c->error = PA_OK;
     c->state = PA_CONTEXT_UNCONNECTED;
     c->ctag = 0;
+    c->csyncid = 0;
 
     c->state_callback = NULL;
     c->state_userdata = NULL;
@@ -234,14 +237,24 @@ void pa_context_set_state(pa_context *c, pa_context_state_t st) {
 
 void pa_context_fail(pa_context *c, int error) {
     assert(c);
-    c->error = error;
+
+    pa_context_set_error(c, error);
     pa_context_set_state(c, PA_CONTEXT_FAILED);
 }
 
+int pa_context_set_error(pa_context *c, int error) {
+    assert(error >= 0 && error < PA_ERR_MAX);
+
+    if (c)
+        c->error = error;
+
+    return error;
+}
+
 static void pstream_die_callback(pa_pstream *p, void *userdata) {
     pa_context *c = userdata;
     assert(p && c);
-    pa_context_fail(c, PA_ERROR_CONNECTIONTERMINATED);
+    pa_context_fail(c, PA_ERR_CONNECTIONTERMINATED);
 }
 
 static void pstream_packet_callback(pa_pstream *p, pa_packet *packet, void *userdata) {
@@ -252,34 +265,34 @@ static void pstream_packet_callback(pa_pstream *p, pa_packet *packet, void *user
     
     if (pa_pdispatch_run(c->pdispatch, packet, c) < 0) {
         pa_log(__FILE__": invalid packet.\n");
-        pa_context_fail(c, PA_ERROR_PROTOCOL);
+        pa_context_fail(c, PA_ERR_PROTOCOL);
     }
 
     pa_context_unref(c);
 }
 
-static void pstream_memblock_callback(pa_pstream *p, uint32_t channel, PA_GCC_UNUSED uint32_t delta, const pa_memchunk *chunk, void *userdata) {
+static void pstream_memblock_callback(pa_pstream *p, uint32_t channel, int64_t offset, pa_seek_mode_t seek, const pa_memchunk *chunk, void *userdata) {
     pa_context *c = userdata;
     pa_stream *s;
-    assert(p && chunk && c && chunk->memblock && chunk->memblock->data);
+    
+    assert(p);
+    assert(chunk);
+    assert(chunk->memblock);
+    assert(chunk->length);
+    assert(c);
 
     pa_context_ref(c);
     
     if ((s = pa_dynarray_get(c->record_streams, channel))) {
-        pa_mcalign_push(s->mcalign, chunk);
 
-        for (;;) {
-            pa_memchunk t;
-
-            if (pa_mcalign_pop(s->mcalign, &t) < 0)
-                break;
+        pa_memblockq_seek(s->record_memblockq, offset, seek);
+        pa_memblockq_push_align(s->record_memblockq, chunk);
 
-            assert(s->record_memblockq);
-            pa_memblockq_push(s->record_memblockq, &t, 0);
-            if (s->read_callback)
-                s->read_callback(s, pa_stream_readable_size(s), s->read_userdata);
+        if (s->read_callback) {
+            size_t l;
 
-            pa_memblock_unref(t.memblock);
+            if ((l = pa_memblockq_get_length(s->record_memblockq)) > 0)
+                s->read_callback(s, l, s->read_userdata);
         }
     }
 
@@ -293,14 +306,14 @@ int pa_context_handle_error(pa_context *c, uint32_t command, pa_tagstruct *t) {
         assert(t);
         
         if (pa_tagstruct_getu32(t, &c->error) < 0) {
-            pa_context_fail(c, PA_ERROR_PROTOCOL);
+            pa_context_fail(c, PA_ERR_PROTOCOL);
             return -1;
                 
         }
     } else if (command == PA_COMMAND_TIMEOUT)
-        c->error = PA_ERROR_TIMEOUT;
+        c->error = PA_ERR_TIMEOUT;
     else {
-        pa_context_fail(c, PA_ERROR_PROTOCOL);
+        pa_context_fail(c, PA_ERR_PROTOCOL);
         return -1;
     }
 
@@ -316,7 +329,7 @@ static void setup_complete_callback(pa_pdispatch *pd, uint32_t command, uint32_t
     if (command != PA_COMMAND_REPLY) {
         
         if (pa_context_handle_error(c, command, t) < 0)
-            pa_context_fail(c, PA_ERROR_PROTOCOL);
+            pa_context_fail(c, PA_ERR_PROTOCOL);
 
         pa_context_fail(c, c->error);
         goto finish;
@@ -368,7 +381,7 @@ static void setup_context(pa_context *c, pa_iochannel *io) {
     assert(c->pdispatch);
 
     if (!c->conf->cookie_valid) {
-        pa_context_fail(c, PA_ERROR_AUTHKEY);
+        pa_context_fail(c, PA_ERR_AUTHKEY);
         goto finish;
     }
 
@@ -401,7 +414,7 @@ static int context_connect_spawn(pa_context *c) {
     
     if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) < 0) {
         pa_log(__FILE__": socketpair() failed: %s\n", strerror(errno));
-        pa_context_fail(c, PA_ERROR_INTERNAL);
+        pa_context_fail(c, PA_ERR_INTERNAL);
         goto fail;
     }
 
@@ -415,7 +428,7 @@ static int context_connect_spawn(pa_context *c) {
 
     if ((pid = fork()) < 0) {
         pa_log(__FILE__": fork() failed: %s\n", strerror(errno));
-        pa_context_fail(c, PA_ERROR_INTERNAL);
+        pa_context_fail(c, PA_ERR_INTERNAL);
 
         if (c->spawn_api.postfork)
             c->spawn_api.postfork();
@@ -471,10 +484,10 @@ static int context_connect_spawn(pa_context *c) {
         
     if (r < 0) {
         pa_log(__FILE__": waitpid() failed: %s\n", strerror(errno));
-        pa_context_fail(c, PA_ERROR_INTERNAL);
+        pa_context_fail(c, PA_ERR_INTERNAL);
         goto fail;
     } else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
-        pa_context_fail(c, PA_ERROR_CONNECTIONREFUSED);
+        pa_context_fail(c, PA_ERR_CONNECTIONREFUSED);
         goto fail;
     }
 
@@ -527,7 +540,7 @@ static int try_next_connection(pa_context *c) {
             }
 #endif
             
-            pa_context_fail(c, PA_ERROR_CONNECTIONREFUSED);
+            pa_context_fail(c, PA_ERR_CONNECTIONREFUSED);
             goto finish;
         }
         
@@ -569,7 +582,7 @@ static void on_connection(pa_socket_client *client, pa_iochannel*io, void *userd
             goto finish;
         }
 
-        pa_context_fail(c, PA_ERROR_CONNECTIONREFUSED);
+        pa_context_fail(c, PA_ERR_CONNECTIONREFUSED);
         goto finish;
     }
 
@@ -593,7 +606,7 @@ int pa_context_connect(pa_context *c, const char *server, int spawn, const pa_sp
     
     if (server) {
         if (!(c->server_list = pa_strlist_parse(server))) {
-            pa_context_fail(c, PA_ERROR_INVALIDSERVER);
+            pa_context_fail(c, PA_ERR_INVALIDSERVER);
             goto finish;
         }
     } else {
@@ -759,7 +772,7 @@ void pa_context_simple_ack_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_U
 
         success = 0;
     } else if (!pa_tagstruct_eof(t)) {
-        pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(o->context, PA_ERR_PROTOCOL);
         goto finish;
     }
 
diff --git a/src/polyp/def.h b/src/polyp/def.h
index ba35b31..f8e0bed 100644
--- a/src/polyp/def.h
+++ b/src/polyp/def.h
@@ -47,7 +47,7 @@ typedef enum pa_context_state {
 
 /** The state of a stream */
 typedef enum pa_stream_state {
-    PA_STREAM_DISCONNECTED, /**< The stream is not yet connected to any sink or source */
+    PA_STREAM_UNCONNECTED, /**< The stream is not yet connected to any sink or source */
     PA_STREAM_CREATING,     /**< The stream is being created */
     PA_STREAM_READY,        /**< The stream is established, you may pass audio data to it now */
     PA_STREAM_FAILED,       /**< An error occured that made the stream invalid */
@@ -103,22 +103,24 @@ typedef struct pa_buffer_attr {
 
 /** Error values as used by pa_context_errno(). Use pa_strerror() to convert these values to human readable strings */
 enum {
-    PA_ERROR_OK,                     /**< No error */
-    PA_ERROR_ACCESS,                 /**< Access failure */
-    PA_ERROR_COMMAND,                /**< Unknown command */
-    PA_ERROR_INVALID,                /**< Invalid argument */
-    PA_ERROR_EXIST,                  /**< Entity exists */
-    PA_ERROR_NOENTITY,               /**< No such entity */
-    PA_ERROR_CONNECTIONREFUSED,      /**< Connection refused */
-    PA_ERROR_PROTOCOL,               /**< Protocol error */ 
-    PA_ERROR_TIMEOUT,                /**< Timeout */
-    PA_ERROR_AUTHKEY,                /**< No authorization key */
-    PA_ERROR_INTERNAL,               /**< Internal error */
-    PA_ERROR_CONNECTIONTERMINATED,   /**< Connection terminated */
-    PA_ERROR_KILLED,                 /**< Entity killed */
-    PA_ERROR_INVALIDSERVER,          /**< Invalid server */
-    PA_ERROR_INITFAILED,             /**< Module initialization failed */
-    PA_ERROR_MAX                     /**< Not really an error but the first invalid error code */
+    PA_OK = 0,                     /**< No error */
+    PA_ERR_ACCESS,                 /**< Access failure */
+    PA_ERR_COMMAND,                /**< Unknown command */
+    PA_ERR_INVALID,                /**< Invalid argument */
+    PA_ERR_EXIST,                  /**< Entity exists */
+    PA_ERR_NOENTITY,               /**< No such entity */
+    PA_ERR_CONNECTIONREFUSED,      /**< Connection refused */
+    PA_ERR_PROTOCOL,               /**< Protocol error */ 
+    PA_ERR_TIMEOUT,                /**< Timeout */
+    PA_ERR_AUTHKEY,                /**< No authorization key */
+    PA_ERR_INTERNAL,               /**< Internal error */
+    PA_ERR_CONNECTIONTERMINATED,   /**< Connection terminated */
+    PA_ERR_KILLED,                 /**< Entity killed */
+    PA_ERR_INVALIDSERVER,          /**< Invalid server */
+    PA_ERR_MODINITFAILED,          /**< Module initialization failed */
+    PA_ERR_BADSTATE,               /**< Bad state */
+    PA_ERR_NODATA,                 /**< No data */ 
+    PA_ERR_MAX                     /**< Not really an error but the first invalid error code */
 };
 
 /** Subscription event mask, as used by pa_context_subscribe() */
@@ -208,6 +210,15 @@ typedef struct pa_spawn_api {
                                 * passed to the new process. */
 } pa_spawn_api;
 
+/** Seek type \since 0.8*/
+typedef enum pa_seek_mode {
+    PA_SEEK_RELATIVE = 0,           /**< Seek relatively to the write index */
+    PA_SEEK_ABSOLUTE = 1,           /**< Seek relatively to the start of the buffer queue */  
+    PA_SEEK_RELATIVE_ON_READ = 2,   /**< Seek relatively to the read index */
+    PA_SEEK_RELATIVE_END = 3,       /**< Seek relatively to the current end of the buffer queue */
+} pa_seek_mode_t;
+
+
 PA_C_DECL_END
 
 #endif
diff --git a/src/polyp/error.c b/src/polyp/error.c
index ece77bf..eff37cc 100644
--- a/src/polyp/error.c
+++ b/src/polyp/error.c
@@ -30,25 +30,28 @@
 
 #include "error.h"
 
-static const char* const errortab[PA_ERROR_MAX] = {
-    [PA_ERROR_OK] = "OK",
-    [PA_ERROR_ACCESS] = "Access denied",
-    [PA_ERROR_COMMAND] = "Unknown command",
-    [PA_ERROR_INVALID] = "Invalid argument",
-    [PA_ERROR_EXIST] = "Entity exists",
-    [PA_ERROR_NOENTITY] = "No such entity",
-    [PA_ERROR_CONNECTIONREFUSED] = "Connection refused",
-    [PA_ERROR_PROTOCOL] = "Protocol error",
-    [PA_ERROR_TIMEOUT] = "Timeout",
-    [PA_ERROR_AUTHKEY] = "No authorization key",
-    [PA_ERROR_INTERNAL] = "Internal error",
-    [PA_ERROR_CONNECTIONTERMINATED] = "Connection terminated",
-    [PA_ERROR_KILLED] = "Entity killed",
-    [PA_ERROR_INVALIDSERVER] = "Invalid server",
+static const char* const errortab[PA_ERR_MAX] = {
+    [PA_OK] = "OK",
+    [PA_ERR_ACCESS] = "Access denied",
+    [PA_ERR_COMMAND] = "Unknown command",
+    [PA_ERR_INVALID] = "Invalid argument",
+    [PA_ERR_EXIST] = "Entity exists",
+    [PA_ERR_NOENTITY] = "No such entity",
+    [PA_ERR_CONNECTIONREFUSED] = "Connection refused",
+    [PA_ERR_PROTOCOL] = "Protocol error",
+    [PA_ERR_TIMEOUT] = "Timeout",
+    [PA_ERR_AUTHKEY] = "No authorization key",
+    [PA_ERR_INTERNAL] = "Internal error",
+    [PA_ERR_CONNECTIONTERMINATED] = "Connection terminated",
+    [PA_ERR_KILLED] = "Entity killed",
+    [PA_ERR_INVALIDSERVER] = "Invalid server",
+    [PA_ERR_MODINITFAILED] = "Module initalization failed",
+    [PA_ERR_BADSTATE] = "Bad state",
+    [PA_ERR_NODATA] = "No data",
 };
 
-const char*pa_strerror(uint32_t error) {
-    if (error >= PA_ERROR_MAX)
+const char*pa_strerror(int error) {
+    if (error < 0 || error >= PA_ERR_MAX)
         return NULL;
 
     return errortab[error];
diff --git a/src/polyp/error.h b/src/polyp/error.h
index ff2507b..9856c1a 100644
--- a/src/polyp/error.h
+++ b/src/polyp/error.h
@@ -31,7 +31,7 @@
 PA_C_DECL_BEGIN
 
 /** Return a human readable error message for the specified numeric error code */
-const char* pa_strerror(uint32_t error);
+const char* pa_strerror(int error);
 
 PA_C_DECL_END
 
diff --git a/src/polyp/internal.h b/src/polyp/internal.h
index 7f4d38a..578969e 100644
--- a/src/polyp/internal.h
+++ b/src/polyp/internal.h
@@ -54,8 +54,9 @@ struct pa_context {
     pa_dynarray *record_streams, *playback_streams;
     PA_LLIST_HEAD(pa_stream, streams);
     PA_LLIST_HEAD(pa_operation, operations);
-    
+
     uint32_t ctag;
+    uint32_t csyncid;
     uint32_t error;
     pa_context_state_t state;
     
@@ -90,6 +91,7 @@ struct pa_stream {
     pa_sample_spec sample_spec;
     pa_channel_map channel_map;
     uint32_t channel;
+    uint32_t syncid;
     int channel_valid;
     uint32_t device_index;
     pa_stream_direction_t direction;
@@ -98,7 +100,6 @@ struct pa_stream {
     pa_usec_t previous_time;
     pa_usec_t previous_ipol_time;
     pa_stream_state_t state;
-    pa_mcalign *mcalign;
     pa_memchunk peek_memchunk;
     pa_memblockq *record_memblockq;
 
@@ -110,14 +111,20 @@ struct pa_stream {
     pa_time_event *ipol_event;
     int ipol_requested;
     
-    void (*state_callback)(pa_stream*c, void *userdata);
+    pa_stream_notify_cb_t state_callback;
     void *state_userdata;
 
-    void (*read_callback)(pa_stream *p, size_t length, void *userdata);
+    pa_stream_request_cb_t read_callback;
     void *read_userdata;
 
-    void (*write_callback)(pa_stream *p, size_t length, void *userdata);
+    pa_stream_request_cb_t write_callback;
     void *write_userdata;
+
+    pa_stream_notify_cb_t overflow_callback;
+    void *overflow_userdata;
+
+    pa_stream_notify_cb_t underflow_callback;
+    void *underflow_userdata;
 };
 
 typedef void (*pa_operation_callback)(void);
@@ -136,6 +143,7 @@ struct pa_operation {
 void pa_command_request(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 void pa_command_stream_killed(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 void pa_command_subscribe_event(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
+void pa_command_overflow_or_underflow(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 
 pa_operation *pa_operation_new(pa_context *c, pa_stream *s);
 void pa_operation_done(pa_operation *o);
@@ -146,6 +154,7 @@ void pa_context_simple_ack_callback(pa_pdispatch *pd, uint32_t command, uint32_t
 void pa_stream_simple_ack_callback(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 
 void pa_context_fail(pa_context *c, int error);
+int pa_context_set_error(pa_context *c, int error);
 void pa_context_set_state(pa_context *c, pa_context_state_t st);
 int pa_context_handle_error(pa_context *c, uint32_t command, pa_tagstruct *t);
 pa_operation* pa_context_send_simple_command(pa_context *c, uint32_t command, void (*internal_callback)(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata), void (*cb)(void), void *userdata);
@@ -154,5 +163,23 @@ void pa_stream_set_state(pa_stream *s, pa_stream_state_t st);
 
 void pa_stream_trash_ipol(pa_stream *s);
 
+#define PA_CHECK_VALIDITY(context, expression, error) do { \
+        if (!(expression)) \
+            return -pa_context_set_error((context), (error)); \
+} while(0)
+
+#define PA_CHECK_VALIDITY_RETURN_NULL(context, expression, error) do { \
+        if (!(expression)) { \
+            pa_context_set_error((context), (error)); \
+            return NULL; \
+        } \
+} while(0)
+
+#define PA_CHECK_VALIDITY_RETURN_ANY(context, expression, error, value) do { \
+        if (!(expression)) { \
+            pa_context_set_error((context), (error)); \
+            return value; \
+        } \
+} while(0)
 
 #endif
diff --git a/src/polyp/introspect.c b/src/polyp/introspect.c
index 4af724b..75ce3ff 100644
--- a/src/polyp/introspect.c
+++ b/src/polyp/introspect.c
@@ -52,7 +52,7 @@ static void context_stat_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UNU
                pa_tagstruct_getu32(t, &i.memblock_allocated_size) < 0 ||
                pa_tagstruct_getu32(t, &i.scache_size) < 0 ||
                !pa_tagstruct_eof(t)) {
-        pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(o->context, PA_ERR_PROTOCOL);
         goto finish;
     }
 
@@ -92,7 +92,7 @@ static void context_get_server_info_callback(pa_pdispatch *pd, uint32_t command,
                pa_tagstruct_getu32(t, &i.cookie) < 0 ||
                !pa_tagstruct_eof(t)) {
 
-        pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(o->context, PA_ERR_PROTOCOL);
         goto finish;
     }
     
@@ -139,7 +139,7 @@ static void context_get_sink_info_callback(pa_pdispatch *pd, uint32_t command, P
                 pa_tagstruct_get_usec(t, &i.latency) < 0 ||
                 pa_tagstruct_gets(t, &i.driver) < 0) {
                 
-                pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+                pa_context_fail(o->context, PA_ERR_PROTOCOL);
                 goto finish;
             }
 
@@ -234,7 +234,7 @@ static void context_get_source_info_callback(pa_pdispatch *pd, uint32_t command,
                 pa_tagstruct_get_usec(t, &i.latency) < 0 ||
                 pa_tagstruct_gets(t, &i.driver) < 0) {
                 
-                pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+                pa_context_fail(o->context, PA_ERR_PROTOCOL);
                 goto finish;
             }
 
@@ -322,7 +322,7 @@ static void context_get_client_info_callback(pa_pdispatch *pd, uint32_t command,
                 pa_tagstruct_gets(t, &i.name) < 0 ||
                 pa_tagstruct_getu32(t, &i.owner_module) < 0 ||
                 pa_tagstruct_gets(t, &i.driver) < 0 ) {
-                pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+                pa_context_fail(o->context, PA_ERR_PROTOCOL);
                 goto finish;
             }
 
@@ -389,7 +389,7 @@ static void context_get_module_info_callback(pa_pdispatch *pd, uint32_t command,
                 pa_tagstruct_gets(t, &i.argument) < 0 ||
                 pa_tagstruct_getu32(t, &i.n_used) < 0 ||
                 pa_tagstruct_get_boolean(t, &i.auto_unload) < 0) {
-                pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+                pa_context_fail(o->context, PA_ERR_PROTOCOL);
                 goto finish;
             }
 
@@ -464,7 +464,7 @@ static void context_get_sink_input_info_callback(pa_pdispatch *pd, uint32_t comm
                 pa_tagstruct_gets(t, &i.resample_method) < 0 ||
                 pa_tagstruct_gets(t, &i.driver) < 0) {
                 
-                pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+                pa_context_fail(o->context, PA_ERR_PROTOCOL);
                 goto finish;
             }
 
@@ -538,7 +538,7 @@ static void context_get_source_output_info_callback(pa_pdispatch *pd, uint32_t c
                 pa_tagstruct_gets(t, &i.resample_method) < 0 ||
                 pa_tagstruct_gets(t, &i.driver) < 0) {
                 
-                pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+                pa_context_fail(o->context, PA_ERR_PROTOCOL);
                 goto finish;
             }
 
@@ -677,7 +677,7 @@ static void context_get_sample_info_callback(pa_pdispatch *pd, uint32_t command,
                 pa_tagstruct_get_boolean(t, &i.lazy) < 0 ||
                 pa_tagstruct_gets(t, &i.filename) < 0) {
                 
-                pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+                pa_context_fail(o->context, PA_ERR_PROTOCOL);
                 goto finish;
             }
 
@@ -787,7 +787,7 @@ static void load_module_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUS
 
     } else if (pa_tagstruct_getu32(t, &idx) < 0 ||
                !pa_tagstruct_eof(t)) {
-        pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(o->context, PA_ERR_PROTOCOL);
         goto finish;
     }
     
@@ -848,7 +848,7 @@ static void context_get_autoload_info_callback(pa_pdispatch *pd, uint32_t comman
                 pa_tagstruct_getu32(t, &i.type) < 0 ||
                 pa_tagstruct_gets(t, &i.module) < 0 ||
                 pa_tagstruct_gets(t, &i.argument) < 0) {
-                pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+                pa_context_fail(o->context, PA_ERR_PROTOCOL);
                 goto finish;
             }
 
@@ -926,7 +926,7 @@ static void context_add_autoload_callback(pa_pdispatch *pd, uint32_t command, PA
         idx = PA_INVALID_INDEX;
     } else if (pa_tagstruct_getu32(t, &idx) ||
                !pa_tagstruct_eof(t)) {
-        pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(o->context, PA_ERR_PROTOCOL);
         goto finish;
     }
 
diff --git a/src/polyp/simple.c b/src/polyp/simple.c
index e14cab2..8a20c22 100644
--- a/src/polyp/simple.c
+++ b/src/polyp/simple.c
@@ -45,13 +45,11 @@ struct pa_simple {
 
     int dead;
 
-    void *read_data;
+    const void *read_data;
     size_t read_index, read_length;
     pa_usec_t latency;
 };
 
-static void read_callback(pa_stream *s, const void*data, size_t length, void *userdata);
-
 static int check_error(pa_simple *p, int *rerror) {
     pa_context_state_t cst;
     pa_stream_state_t sst;
@@ -92,7 +90,7 @@ static int iterate(pa_simple *p, int block, int *rerror) {
     do {
         if (pa_mainloop_iterate(p->mainloop, 1, NULL) < 0) {
             if (rerror)
-                *rerror = PA_ERROR_INTERNAL;
+                *rerror = PA_ERR_INTERNAL;
             return -1;
         }
 
@@ -106,7 +104,7 @@ static int iterate(pa_simple *p, int block, int *rerror) {
 
         if (pa_mainloop_iterate(p->mainloop, 0, NULL) < 0) {
             if (rerror)
-                *rerror = PA_ERROR_INTERNAL;
+                *rerror = PA_ERR_INTERNAL;
             return -1;
         }
 
@@ -128,7 +126,7 @@ pa_simple* pa_simple_new(
     int *rerror) {
     
     pa_simple *p;
-    int error = PA_ERROR_INTERNAL;
+    int error = PA_ERR_INTERNAL;
     assert(ss && (dir == PA_STREAM_PLAYBACK || dir == PA_STREAM_RECORD));
 
     p = pa_xmalloc(sizeof(pa_simple));
@@ -157,7 +155,7 @@ pa_simple* pa_simple_new(
         goto fail;
 
     if (dir == PA_STREAM_PLAYBACK)
-        pa_stream_connect_playback(p->stream, dev, attr, 0, NULL);
+        pa_stream_connect_playback(p->stream, dev, attr, 0, NULL, NULL);
     else
         pa_stream_connect_record(p->stream, dev, attr, 0);
 
@@ -167,8 +165,6 @@ pa_simple* pa_simple_new(
             goto fail;
     }
 
-    pa_stream_set_read_callback(p->stream, read_callback, p);
-    
     return p;
     
 fail:
@@ -181,8 +177,6 @@ fail:
 void pa_simple_free(pa_simple *s) {
     assert(s);
 
-    pa_xfree(s->read_data);
-
     if (s->stream)
         pa_stream_unref(s->stream);
     
@@ -215,7 +209,7 @@ int pa_simple_write(pa_simple *p, const void*data, size_t length, int *rerror) {
         if (l > length)
             l = length;
 
-        pa_stream_write(p->stream, data, l, NULL, 0);
+        pa_stream_write(p->stream, data, l, NULL, 0, PA_SEEK_RELATIVE);
         data = (const uint8_t*) data + l;
         length -= l;
     }
@@ -227,19 +221,6 @@ int pa_simple_write(pa_simple *p, const void*data, size_t length, int *rerror) {
     return 0;
 }
 
-static void read_callback(pa_stream *s, const void*data, size_t length, void *userdata) {
-    pa_simple *p = userdata;
-    assert(s && data && length && p);
-
-    if (p->read_data) {
-        pa_log(__FILE__": Buffer overflow, dropping incoming memory blocks.\n");
-        pa_xfree(p->read_data);
-    }
-
-    p->read_data = pa_xmemdup(data, p->read_length = length);
-    p->read_index = 0;
-}
-
 int pa_simple_read(pa_simple *p, void*data, size_t length, int *rerror) {
     assert(p && data && p->direction == PA_STREAM_RECORD);
 
@@ -251,13 +232,18 @@ int pa_simple_read(pa_simple *p, void*data, size_t length, int *rerror) {
     }
     
     while (length > 0) {
+
+        if (!p->read_data) 
+            if (pa_stream_peek(p->stream, &p->read_data, &p->read_length) >= 0)
+                p->read_index = 0;
+        
         if (p->read_data) {
             size_t l = length;
 
             if (p->read_length <= l)
                 l = p->read_length;
 
-            memcpy(data, (uint8_t*) p->read_data+p->read_index, l);
+            memcpy(data, (const uint8_t*) p->read_data+p->read_index, l);
 
             data = (uint8_t*) data + l;
             length -= l;
@@ -266,8 +252,9 @@ int pa_simple_read(pa_simple *p, void*data, size_t length, int *rerror) {
             p->read_length -= l;
 
             if (!p->read_length) {
-                pa_xfree(p->read_data);
+                pa_stream_drop(p->stream);
                 p->read_data = NULL;
+                p->read_length = 0;
                 p->read_index = 0;
             }
             
diff --git a/src/polyp/stream.c b/src/polyp/stream.c
index 35de2d0..5497f0c 100644
--- a/src/polyp/stream.c
+++ b/src/polyp/stream.c
@@ -28,6 +28,7 @@
 #include <stdio.h>
 #include <string.h>
 
+#include <polyp/def.h>
 #include <polypcore/xmalloc.h>
 #include <polypcore/pstream-util.h>
 #include <polypcore/util.h>
@@ -39,14 +40,11 @@
 
 pa_stream *pa_stream_new(pa_context *c, const char *name, const pa_sample_spec *ss, const pa_channel_map *map) {
     pa_stream *s;
+    
     assert(c);
-    assert(ss);
-
-    if (!pa_sample_spec_valid(ss))
-        return NULL;
 
-    if (map && !pa_channel_map_valid(map))
-        return NULL;
+    PA_CHECK_VALIDITY_RETURN_NULL(c, ss && pa_sample_spec_valid(ss), PA_ERR_INVALID);
+    PA_CHECK_VALIDITY_RETURN_NULL(c, !map || pa_channel_map_valid(map), PA_ERR_INVALID);
 
     s = pa_xnew(pa_stream, 1);
     s->ref = 1;
@@ -59,6 +57,10 @@ pa_stream *pa_stream_new(pa_context *c, const char *name, const pa_sample_spec *
     s->write_userdata = NULL;
     s->state_callback = NULL;
     s->state_userdata = NULL;
+    s->overflow_callback = NULL;
+    s->overflow_userdata = NULL;
+    s->underflow_callback = NULL;
+    s->underflow_userdata = NULL;
 
     s->direction = PA_STREAM_NODIRECTION;
     s->name = pa_xstrdup(name);
@@ -71,13 +73,13 @@ pa_stream *pa_stream_new(pa_context *c, const char *name, const pa_sample_spec *
     
     s->channel = 0;
     s->channel_valid = 0;
+    s->syncid = c->csyncid++;
     s->device_index = PA_INVALID_INDEX;
     s->requested_bytes = 0;
-    s->state = PA_STREAM_DISCONNECTED;
+    s->state = PA_STREAM_UNCONNECTED;
     memset(&s->buffer_attr, 0, sizeof(s->buffer_attr));
 
-    s->mcalign = pa_mcalign_new(pa_frame_size(ss), c->memblock_stat);
-
+    s->peek_memchunk.index = 0;
     s->peek_memchunk.length = 0;
     s->peek_memchunk.memblock = NULL;
 
@@ -114,42 +116,52 @@ static void stream_free(pa_stream *s) {
     if (s->record_memblockq)
         pa_memblockq_free(s->record_memblockq);
 
-    pa_mcalign_free(s->mcalign);
-    
     pa_xfree(s->name);
     pa_xfree(s);
 }
 
 void pa_stream_unref(pa_stream *s) {
-    assert(s && s->ref >= 1);
+    assert(s);
+    assert(s->ref >= 1);
 
     if (--(s->ref) == 0)
         stream_free(s);
 }
 
 pa_stream* pa_stream_ref(pa_stream *s) {
-    assert(s && s->ref >= 1);
+    assert(s);
+    assert(s->ref >= 1);
+    
     s->ref++;
     return s;
 }
 
 pa_stream_state_t pa_stream_get_state(pa_stream *s) {
-    assert(s && s->ref >= 1);
+    assert(s);
+    assert(s->ref >= 1);
+    
     return s->state;
 }
 
 pa_context* pa_stream_get_context(pa_stream *s) {
-    assert(s && s->ref >= 1);
+    assert(s);
+    assert(s->ref >= 1);
+    
     return s->context;
 }
 
 uint32_t pa_stream_get_index(pa_stream *s) {
-    assert(s && s->ref >= 1);
+    assert(s);
+    assert(s->ref >= 1);
+
+    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE, PA_INVALID_INDEX);
+    
     return s->device_index;
 }
     
 void pa_stream_set_state(pa_stream *s, pa_stream_state_t st) {
-    assert(s && s->ref >= 1);
+    assert(s);
+    assert(s->ref >= 1);
 
     if (s->state == st)
         return;
@@ -159,6 +171,8 @@ void pa_stream_set_state(pa_stream *s, pa_stream_state_t st) {
     s->state = st;
     
     if ((st == PA_STREAM_FAILED || st == PA_STREAM_TERMINATED) && s->context) {
+        /* Detach from context */
+        
         if (s->channel_valid)
             pa_dynarray_put((s->direction == PA_STREAM_PLAYBACK) ? s->context->playback_streams : s->context->record_streams, s->channel, NULL);
 
@@ -182,14 +196,14 @@ void pa_command_stream_killed(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED
     
     if (pa_tagstruct_getu32(t, &channel) < 0 ||
         !pa_tagstruct_eof(t)) {
-        pa_context_fail(c, PA_ERROR_PROTOCOL);
+        pa_context_fail(c, PA_ERR_PROTOCOL);
         goto finish;
     }
     
     if (!(s = pa_dynarray_get(command == PA_COMMAND_PLAYBACK_STREAM_KILLED ? c->playback_streams : c->record_streams, channel)))
         goto finish;
 
-    c->error = PA_ERROR_KILLED;
+    c->error = PA_ERR_KILLED;
     pa_stream_set_state(s, PA_STREAM_FAILED);
 
 finish:
@@ -207,24 +221,55 @@ void pa_command_request(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32
     if (pa_tagstruct_getu32(t, &channel) < 0 ||
         pa_tagstruct_getu32(t, &bytes) < 0 ||
         !pa_tagstruct_eof(t)) {
-        pa_context_fail(c, PA_ERROR_PROTOCOL);
+        pa_context_fail(c, PA_ERR_PROTOCOL);
         goto finish;
     }
     
     if (!(s = pa_dynarray_get(c->playback_streams, channel)))
         goto finish;
 
-    if (s->state != PA_STREAM_READY)
-        goto finish;
+    if (s->state == PA_STREAM_READY) {
+        s->requested_bytes += bytes;
+        
+        if (s->requested_bytes > 0 && s->write_callback)
+            s->write_callback(s, s->requested_bytes, s->write_userdata);
+    }
 
-    pa_stream_ref(s);
+finish:
+    pa_context_unref(c);
+}
+
+void pa_command_overflow_or_underflow(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32_t tag, pa_tagstruct *t, void *userdata) {
+    pa_stream *s;
+    pa_context *c = userdata;
+    uint32_t channel;
+
+    assert(pd);
+    assert(command == PA_COMMAND_OVERFLOW || command == PA_COMMAND_UNDERFLOW);
+    assert(t);
+    assert(c);
+
+    pa_context_ref(c);
+    
+    if (pa_tagstruct_getu32(t, &channel) < 0 ||
+        !pa_tagstruct_eof(t)) {
+        pa_context_fail(c, PA_ERR_PROTOCOL);
+        goto finish;
+    }
     
-    s->requested_bytes += bytes;
+    if (!(s = pa_dynarray_get(c->playback_streams, channel)))
+        goto finish;
 
-    if (s->requested_bytes && s->write_callback)
-        s->write_callback(s, s->requested_bytes, s->write_userdata);
+    if (s->state == PA_STREAM_READY) {
 
-    pa_stream_unref(s);
+        if (command == PA_COMMAND_OVERFLOW) {
+            if (s->overflow_callback)
+                s->overflow_callback(s, s->overflow_userdata);
+        } else if (command == PA_COMMAND_UNDERFLOW) {
+            if (s->underflow_callback)
+                s->underflow_callback(s, s->underflow_userdata);
+        }
+    }
 
 finish:
     pa_context_unref(c);
@@ -270,14 +315,21 @@ void pa_create_stream_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED
         ((s->direction != PA_STREAM_UPLOAD) && pa_tagstruct_getu32(t, &s->device_index) < 0) ||
         ((s->direction != PA_STREAM_RECORD) && pa_tagstruct_getu32(t, &s->requested_bytes) < 0) ||
         !pa_tagstruct_eof(t)) {
-        pa_context_fail(s->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(s->context, PA_ERR_PROTOCOL);
         goto finish;
     }
 
     if (s->direction == PA_STREAM_RECORD) {
         assert(!s->record_memblockq);
-        s->record_memblockq = pa_memblockq_new(s->buffer_attr.maxlength, 0,
-            pa_frame_size(&s->sample_spec), 0, 0, s->context->memblock_stat);
+        s->record_memblockq = pa_memblockq_new(
+                0, 
+                s->buffer_attr.maxlength,
+                0,
+                pa_frame_size(&s->sample_spec),
+                1,
+                0,
+                NULL,
+                s->context->memblock_stat);
         assert(s->record_memblockq);
     }
 
@@ -303,13 +355,32 @@ finish:
     pa_stream_unref(s);
 }
 
-static void create_stream(pa_stream *s, const char *dev, const pa_buffer_attr *attr, pa_stream_flags_t flags, const pa_cvolume *volume) {
+static int create_stream(
+        pa_stream_direction_t direction,
+        pa_stream *s,
+        const char *dev,
+        const pa_buffer_attr *attr,
+        pa_stream_flags_t flags,
+        const pa_cvolume *volume,
+        pa_stream *sync_stream) {
+    
     pa_tagstruct *t;
     uint32_t tag;
-    assert(s && s->ref >= 1 && s->state == PA_STREAM_DISCONNECTED);
+    
+    assert(s);
+    assert(s->ref >= 1);
+    
+    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_UNCONNECTED, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY(s->context, (flags & ~(PA_STREAM_START_CORKED|PA_STREAM_INTERPOLATE_LATENCY)) == 0, PA_ERR_INVALID);
+    PA_CHECK_VALIDITY(s->context, direction == PA_STREAM_PLAYBACK || flags == 0, PA_ERR_INVALID);
 
     pa_stream_ref(s);
 
+    s->direction = direction;
+    
+    if (sync_stream)
+        s->syncid = sync_stream->syncid;
+    
     s->interpolate = !!(flags & PA_STREAM_INTERPOLATE_LATENCY);
     pa_stream_trash_ipol(s);
     
@@ -336,25 +407,28 @@ static void create_stream(pa_stream *s, const char *dev, const pa_buffer_attr *a
             dev = s->context->conf->default_source;
     }
     
-    pa_tagstruct_put(t,
-        PA_TAG_U32, s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_CREATE_PLAYBACK_STREAM : PA_COMMAND_CREATE_RECORD_STREAM,
-        PA_TAG_U32, tag = s->context->ctag++,
-        PA_TAG_STRING, s->name,
-        PA_TAG_SAMPLE_SPEC, &s->sample_spec,
-        PA_TAG_CHANNEL_MAP, &s->channel_map,
-        PA_TAG_U32, PA_INVALID_INDEX,
-        PA_TAG_STRING, dev,
-        PA_TAG_U32, s->buffer_attr.maxlength,
-        PA_TAG_BOOLEAN, !!(flags & PA_STREAM_START_CORKED),
-        PA_TAG_INVALID);
+    pa_tagstruct_put(
+            t,
+            PA_TAG_U32, s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_CREATE_PLAYBACK_STREAM : PA_COMMAND_CREATE_RECORD_STREAM,
+            PA_TAG_U32, tag = s->context->ctag++,
+            PA_TAG_STRING, s->name,
+            PA_TAG_SAMPLE_SPEC, &s->sample_spec,
+            PA_TAG_CHANNEL_MAP, &s->channel_map,
+            PA_TAG_U32, PA_INVALID_INDEX,
+            PA_TAG_STRING, dev,
+            PA_TAG_U32, s->buffer_attr.maxlength,
+            PA_TAG_BOOLEAN, !!(flags & PA_STREAM_START_CORKED),
+            PA_TAG_INVALID);
     
     if (s->direction == PA_STREAM_PLAYBACK) {
         pa_cvolume cv;
-        pa_tagstruct_put(t,
-            PA_TAG_U32, s->buffer_attr.tlength,
-            PA_TAG_U32, s->buffer_attr.prebuf,
-            PA_TAG_U32, s->buffer_attr.minreq,
-            PA_TAG_INVALID);
+        pa_tagstruct_put(
+                t,
+                PA_TAG_U32, s->buffer_attr.tlength,
+                PA_TAG_U32, s->buffer_attr.prebuf,
+                PA_TAG_U32, s->buffer_attr.minreq,
+                PA_TAG_U32, s->syncid,
+                PA_TAG_INVALID);
 
         if (!volume) {
             pa_cvolume_reset(&cv, s->sample_spec.channels);
@@ -369,23 +443,57 @@ static void create_stream(pa_stream *s, const char *dev, const pa_buffer_attr *a
     pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, pa_create_stream_callback, s);
 
     pa_stream_unref(s);
+    return 0;
 }
 
-void pa_stream_connect_playback(pa_stream *s, const char *dev, const pa_buffer_attr *attr, pa_stream_flags_t flags, pa_cvolume *volume) {
-    assert(s && s->context->state == PA_CONTEXT_READY && s->ref >= 1);
-    s->direction = PA_STREAM_PLAYBACK;
-    create_stream(s, dev, attr, flags, volume);
+int pa_stream_connect_playback(
+        pa_stream *s,
+        const char *dev,
+        const pa_buffer_attr *attr,
+        pa_stream_flags_t flags,
+        pa_cvolume *volume,
+        pa_stream *sync_stream) {
+    
+    assert(s);
+    assert(s->ref >= 1);
+    
+    return create_stream(PA_STREAM_PLAYBACK, s, dev, attr, flags, volume, sync_stream);
 }
 
-void pa_stream_connect_record(pa_stream *s, const char *dev, const pa_buffer_attr *attr, pa_stream_flags_t flags) {
-    assert(s && s->context->state == PA_CONTEXT_READY && s->ref >= 1);
-    s->direction = PA_STREAM_RECORD;
-    create_stream(s, dev, attr, flags, 0);
+int pa_stream_connect_record(
+        pa_stream *s,
+        const char *dev,
+        const pa_buffer_attr *attr,
+        pa_stream_flags_t flags) {
+    
+    assert(s);
+    assert(s->ref >= 1);
+
+    return create_stream(PA_STREAM_RECORD, s, dev, attr, flags, NULL, NULL);
 }
 
-void pa_stream_write(pa_stream *s, const void *data, size_t length, void (*free_cb)(void *p), size_t delta) {
+int pa_stream_write(
+        pa_stream *s,
+        const void *data,
+        size_t length,
+        void (*free_cb)(void *p),
+        int64_t offset,
+        pa_seek_mode_t seek) {
+    
     pa_memchunk chunk;
-    assert(s && s->context && data && length && s->state == PA_STREAM_READY && s->ref >= 1);
+    
+    assert(s);
+    assert(s->ref >= 1);
+    assert(s->context);
+    assert(data);
+
+    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY(s->context, s->direction == PA_STREAM_PLAYBACK || s->direction == PA_STREAM_UPLOAD, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY(s->context, seek <= PA_SEEK_RELATIVE_END, PA_ERR_INVALID);
+    PA_CHECK_VALIDITY(s->context, s->direction == PA_STREAM_PLAYBACK || (seek == PA_SEEK_RELATIVE && offset == 0), PA_ERR_INVALID);
+
+    if (length <= 0)
+        return 0;
 
     if (free_cb) {
         chunk.memblock = pa_memblock_new_user((void*) data, length, free_cb, 1, s->context->memblock_stat);
@@ -398,7 +506,7 @@ void pa_stream_write(pa_stream *s, const void *data, size_t length, void (*free_
     chunk.index = 0;
     chunk.length = length;
 
-    pa_pstream_send_memblock(s->context->pstream, s->channel, delta, &chunk);
+    pa_pstream_send_memblock(s->context->pstream, s->channel, offset, seek, &chunk);
     pa_memblock_unref(chunk.memblock);
     
     if (length < s->requested_bytes)
@@ -407,72 +515,87 @@ void pa_stream_write(pa_stream *s, const void *data, size_t length, void (*free_
         s->requested_bytes = 0;
 
     s->counter += length;
+    return 0;
 }
 
-void pa_stream_peek(pa_stream *s, void **data, size_t *length) {
-    assert(s && s->record_memblockq && data && length && s->state == PA_STREAM_READY && s->ref >= 1);
+int pa_stream_peek(pa_stream *s, const void **data, size_t *length) {
+    assert(s);
+    assert(s->ref >= 1);
+    assert(data);
+    assert(length);
 
+    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY(s->context, s->direction == PA_STREAM_RECORD, PA_ERR_BADSTATE);
+    
     if (!s->peek_memchunk.memblock) {
-        *data = NULL;
-        *length = 0;
-
-        if (pa_memblockq_peek(s->record_memblockq, &s->peek_memchunk) < 0)
-            return;
 
-        pa_memblockq_drop(s->record_memblockq, &s->peek_memchunk, s->peek_memchunk.length);
+        if (pa_memblockq_peek(s->record_memblockq, &s->peek_memchunk) < 0) {
+            *data = NULL;
+            *length = 0;
+            return 0;
+        }
     }
 
-    *data = (char*)s->peek_memchunk.memblock->data + s->peek_memchunk.index;
+    *data = (const char*) s->peek_memchunk.memblock->data + s->peek_memchunk.index;
     *length = s->peek_memchunk.length;
+    return 0;
 }
 
-void pa_stream_drop(pa_stream *s) {
-    assert(s && s->peek_memchunk.memblock && s->state == PA_STREAM_READY && s->ref >= 1);
-
-    s->counter += s->peek_memchunk.length;
+int pa_stream_drop(pa_stream *s) {
+    assert(s);
+    assert(s->ref >= 1);
 
+    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY(s->context, s->direction == PA_STREAM_RECORD, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY(s->context, s->peek_memchunk.memblock, PA_ERR_BADSTATE);
+    
+    pa_memblockq_drop(s->record_memblockq, &s->peek_memchunk, s->peek_memchunk.length);
+    
     pa_memblock_unref(s->peek_memchunk.memblock);
-
     s->peek_memchunk.length = 0;
+    s->peek_memchunk.index = 0;
     s->peek_memchunk.memblock = NULL;
+
+    s->counter += s->peek_memchunk.length;
+    return 0;
 }
 
 size_t pa_stream_writable_size(pa_stream *s) {
-    assert(s && s->ref >= 1);
-    return s->state == PA_STREAM_READY ? s->requested_bytes : 0;
+    assert(s);
+    assert(s->ref >= 1);
+
+    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE, (size_t) -1);
+    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->direction == PA_STREAM_PLAYBACK, PA_ERR_BADSTATE, (size_t) -1);
+    
+    return s->requested_bytes;
 }
 
 size_t pa_stream_readable_size(pa_stream *s) {
-    size_t sz;
-
-    assert(s && s->ref >= 1);
-
-    if (s->state != PA_STREAM_READY)
-        return 0;
-
-    assert(s->record_memblockq);
-
-    sz = (size_t)pa_memblockq_get_length(s->record_memblockq);
+    assert(s);
+    assert(s->ref >= 1);
 
-    if (s->peek_memchunk.memblock)
-        sz += s->peek_memchunk.length;
+    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE, (size_t) -1);
+    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->direction == PA_STREAM_RECORD, PA_ERR_BADSTATE, (size_t) -1);
 
-    return sz;
+    return pa_memblockq_get_length(s->record_memblockq);
 }
 
 pa_operation * pa_stream_drain(pa_stream *s, void (*cb) (pa_stream*s, int success, void *userdata), void *userdata) {
     pa_operation *o;
     pa_tagstruct *t;
     uint32_t tag;
-    assert(s && s->ref >= 1 && s->state == PA_STREAM_READY);
+    
+    assert(s);
+    assert(s->ref >= 1);
+
+    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction == PA_STREAM_PLAYBACK, PA_ERR_BADSTATE);
 
     o = pa_operation_new(s->context, s);
-    assert(o);
     o->callback = (pa_operation_callback) cb;
     o->userdata = userdata;
 
     t = pa_tagstruct_new(NULL, 0);
-    assert(t);
     pa_tagstruct_putu32(t, PA_COMMAND_DRAIN_PLAYBACK_STREAM);
     pa_tagstruct_putu32(t, tag = s->context->ctag++);
     pa_tagstruct_putu32(t, s->channel);
@@ -501,7 +624,7 @@ static void stream_get_latency_info_callback(pa_pdispatch *pd, uint32_t command,
                pa_tagstruct_get_timeval(t, &remote) < 0 ||
                pa_tagstruct_getu64(t, &i.counter) < 0 ||
                !pa_tagstruct_eof(t)) {
-        pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(o->context, PA_ERR_PROTOCOL);
         goto finish;
     } else {
         pa_gettimeofday(&now);
@@ -549,15 +672,18 @@ pa_operation* pa_stream_get_latency_info(pa_stream *s, void (*cb)(pa_stream *p,
     pa_operation *o;
     pa_tagstruct *t;
     struct timeval now;
-    assert(s && s->direction != PA_STREAM_UPLOAD);
+    
+    assert(s);
+    assert(s->ref >= 1);
 
+    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction != PA_STREAM_UPLOAD, PA_ERR_BADSTATE);
+    
     o = pa_operation_new(s->context, s);
-    assert(o);
     o->callback = (pa_operation_callback) cb;
     o->userdata = userdata;
 
     t = pa_tagstruct_new(NULL, 0);
-    assert(t);
     pa_tagstruct_putu32(t, s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_GET_PLAYBACK_LATENCY : PA_COMMAND_GET_RECORD_LATENCY);
     pa_tagstruct_putu32(t, tag = s->context->ctag++);
     pa_tagstruct_putu32(t, s->channel);
@@ -585,7 +711,7 @@ void pa_stream_disconnect_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UN
         pa_stream_set_state(s, PA_STREAM_FAILED);
         goto finish;
     } else if (!pa_tagstruct_eof(t)) {
-        pa_context_fail(s->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(s->context, PA_ERR_PROTOCOL);
         goto finish;
     }
 
@@ -595,18 +721,19 @@ finish:
     pa_stream_unref(s);
 }
 
-void pa_stream_disconnect(pa_stream *s) {
+int pa_stream_disconnect(pa_stream *s) {
     pa_tagstruct *t;
     uint32_t tag;
-    assert(s && s->ref >= 1);
     
-    if (!s->channel_valid || !s->context->state == PA_CONTEXT_READY)
-        return;
+    assert(s);
+    assert(s->ref >= 1);
+
+    PA_CHECK_VALIDITY(s->context, s->channel_valid, PA_ERR_BADSTATE);
+    PA_CHECK_VALIDITY(s->context, s->context->state == PA_CONTEXT_READY, PA_ERR_BADSTATE);
 
     pa_stream_ref(s);
 
     t = pa_tagstruct_new(NULL, 0);
-    assert(t);
     
     pa_tagstruct_putu32(t, s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_DELETE_PLAYBACK_STREAM :
                         (s->direction == PA_STREAM_RECORD ? PA_COMMAND_DELETE_RECORD_STREAM : PA_COMMAND_DELETE_UPLOAD_STREAM));
@@ -616,26 +743,49 @@ void pa_stream_disconnect(pa_stream *s) {
     pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, pa_stream_disconnect_callback, s);
 
     pa_stream_unref(s);
+    return 0;
 }
 
-void pa_stream_set_read_callback(pa_stream *s, void (*cb)(pa_stream *p, size_t length, void *userdata), void *userdata) {
-    assert(s && s->ref >= 1);
+void pa_stream_set_read_callback(pa_stream *s, pa_stream_request_cb_t cb, void *userdata) {
+    assert(s);
+    assert(s->ref >= 1);
+
     s->read_callback = cb;
     s->read_userdata = userdata;
 }
 
-void pa_stream_set_write_callback(pa_stream *s, void (*cb)(pa_stream *p, size_t length, void *userdata), void *userdata) {
-    assert(s && s->ref >= 1);
+void pa_stream_set_write_callback(pa_stream *s, pa_stream_request_cb_t cb, void *userdata) {
+    assert(s);
+    assert(s->ref >= 1);
+
     s->write_callback = cb;
     s->write_userdata = userdata;
 }
 
-void pa_stream_set_state_callback(pa_stream *s, void (*cb)(pa_stream *s, void *userdata), void *userdata) {
-    assert(s && s->ref >= 1);
+void pa_stream_set_state_callback(pa_stream *s, pa_stream_notify_cb_t cb, void *userdata) {
+    assert(s);
+    assert(s->ref >= 1);
+
     s->state_callback = cb;
     s->state_userdata = userdata;
 }
 
+void pa_stream_set_overflow_callback(pa_stream *s, pa_stream_notify_cb_t cb, void *userdata) {
+    assert(s);
+    assert(s->ref >= 1);
+    
+    s->overflow_callback = cb;
+    s->overflow_userdata = userdata;
+}
+
+void pa_stream_set_underflow_callback(pa_stream *s, pa_stream_notify_cb_t cb, void *userdata) {
+    assert(s);
+    assert(s->ref >= 1);
+    
+    s->underflow_callback = cb;
+    s->underflow_userdata = userdata;
+}
+
 void pa_stream_simple_ack_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32_t tag, pa_tagstruct *t, void *userdata) {
     pa_operation *o = userdata;
     int success = 1;
@@ -647,7 +797,7 @@ void pa_stream_simple_ack_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UN
 
         success = 0;
     } else if (!pa_tagstruct_eof(t)) {
-        pa_context_fail(o->context, PA_ERROR_PROTOCOL);
+        pa_context_fail(o->context, PA_ERR_PROTOCOL);
         goto finish;
     }
 
diff --git a/src/polyp/stream.h b/src/polyp/stream.h
index 9bbda43..ce53596 100644
--- a/src/polyp/stream.h
+++ b/src/polyp/stream.h
@@ -40,8 +40,27 @@ PA_C_DECL_BEGIN
  * An opaque stream for playback or recording */
 typedef struct pa_stream pa_stream;
 
+/** A generic callback for operation completion */
+typedef void (*pa_stream_success_cb_t) (pa_stream*s, int success, void *userdata);
+
+/** A generic free callback */
+typedef void (*pa_free_cb_t)(void *p);
+
+/** A generic request callback */
+typedef void (*pa_stream_request_cb_t)(pa_stream *p, size_t length, void *userdata);
+
+/** A generic notification callback */
+typedef void (*pa_stream_notify_cb_t)(pa_stream *p, void *userdata);
+
+/** Callback prototype for pa_stream_get_latency_info() */
+typedef void (*pa_stream_get_latency_info_cb_t)(pa_stream *p, const pa_latency_info *i, void *userdata);
+
 /** Create a new, unconnected stream with the specified name and sample type */
-pa_stream* pa_stream_new(pa_context *c, const char *name, const pa_sample_spec *ss, const pa_channel_map *map);
+pa_stream* pa_stream_new(
+        pa_context *c,
+        const char *name,
+        const pa_sample_spec *ss,
+        const pa_channel_map *map);
 
 /** Decrease the reference counter by one */
 void pa_stream_unref(pa_stream *s);
@@ -59,108 +78,101 @@ pa_context* pa_stream_get_context(pa_stream *p);
 uint32_t pa_stream_get_index(pa_stream *s);
 
 /** Connect the stream to a sink */
-void pa_stream_connect_playback(
-    pa_stream *s,
-    const char *dev,
-    const pa_buffer_attr *attr,
-    pa_stream_flags_t flags,
-    pa_cvolume *volume);
+int pa_stream_connect_playback(
+        pa_stream *s                  /**< The stream to connect to a sink */,
+        const char *dev               /**< Name of the sink to connect to, or NULL for default */ ,
+        const pa_buffer_attr *attr    /**< Buffering attributes, or NULL for default */,
+        pa_stream_flags_t flags       /**< Additional flags, or 0 for default */,
+        pa_cvolume *volume            /**< Initial volume, or NULL for default */,
+        pa_stream *sync_stream        /**< Synchronize this stream with the specified one, or NULL for a standalone stream*/);
 
 /** Connect the stream to a source */
-void pa_stream_connect_record(
-    pa_stream *s,
-    const char *dev,
-    const pa_buffer_attr *attr,
-    pa_stream_flags_t flags);
+int pa_stream_connect_record(
+        pa_stream *s,
+        const char *dev,
+        const pa_buffer_attr *attr,
+        pa_stream_flags_t flags);
 
 /** Disconnect a stream from a source/sink */
-void pa_stream_disconnect(pa_stream *s);
+int pa_stream_disconnect(pa_stream *s);
 
 /** Write some data to the server (for playback sinks), if free_cb is
  * non-NULL this routine is called when all data has been written out
  * and an internal reference to the specified data is kept, the data
  * is not copied. If NULL, the data is copied into an internal
- * buffer. */ 
-void pa_stream_write(pa_stream *p      /**< The stream to use */,
-                     const void *data         /**< The data to write */,
-                     size_t length            /**< The length of the data to write */,
-                     void (*free_cb)(void *p) /**< A cleanup routine for the data or NULL to request an internal copy */,
-                     size_t delta             /**< Drop this many
-                                                 bytes in the playback
-                                                 buffer before writing
-                                                 this data. Use
-                                                 (size_t) -1 for
-                                                 clearing the whole
-                                                 playback
-                                                 buffer. Normally you
-                                                 will specify 0 here,
-                                                 i.e. append to the
-                                                 playback buffer. If
-                                                 the value given here
-                                                 is greater than the
-                                                 buffered data length
-                                                 the buffer is cleared
-                                                 and the data is
-                                                 written to the
-                                                 buffer's start. This
-                                                 value is ignored on
-                                                 upload streams. */);
-
-/** Read the next fragment from the buffer (for capture sources).
+ * buffer. The client my freely seek around in the output buffer. For
+ * most applications passing 0 and PA_SEEK_RELATIVE as arguments for
+ * offset and seek should be useful.*/ 
+int pa_stream_write(
+        pa_stream *p             /**< The stream to use */,
+        const void *data         /**< The data to write */,
+        size_t length            /**< The length of the data to write */,
+        pa_free_cb_t free_cb     /**< A cleanup routine for the data or NULL to request an internal copy */,
+        int64_t offset,          /**< Offset for seeking, must be 0 for upload streams */
+        pa_seek_mode_t seek      /**< Seek mode, must be PA_SEEK_RELATIVE for upload streams */);
+
+/** Read the next fragment from the buffer (for recording).
  * data will point to the actual data and length will contain the size
  * of the data in bytes (which can be less than a complete framgnet).
- * Use pa_stream_drop() to actually remove the data from the buffer.
- * \since 0.8 */ 
-void pa_stream_peek(pa_stream *p                 /**< The stream to use */,
-                     void **data                 /**< Pointer to pointer that will point to data */,
-                     size_t *length              /**< The length of the data read */);
+ * Use pa_stream_drop() to actually remove the data from the
+ * buffer. If no data is available will return a NULL pointer  \since 0.8 */ 
+int pa_stream_peek(
+        pa_stream *p                 /**< The stream to use */,
+        const void **data            /**< Pointer to pointer that will point to data */,
+        size_t *length              /**< The length of the data read */);
 
 /** Remove the current fragment. It is invalid to do this without first
  * calling pa_stream_peek(). \since 0.8 */
-void pa_stream_drop(pa_stream *p);
+int pa_stream_drop(pa_stream *p);
 
-/** Return the amount of bytes that may be written using pa_stream_write() */
+/** Return the nember of bytes that may be written using pa_stream_write() */
 size_t pa_stream_writable_size(pa_stream *p);
 
-/** Return the ammount of bytes that may be read using pa_stream_read() \since 0.8 */
+/** Return the number of bytes that may be read using pa_stream_read() \since 0.8 */
 size_t pa_stream_readable_size(pa_stream *p);
 
-/** Drain a playback stream */
-pa_operation* pa_stream_drain(pa_stream *s, void (*cb) (pa_stream*s, int success, void *userdata), void *userdata);
+/** Drain a playback stream. Use this for notification when the buffer is empty */
+pa_operation* pa_stream_drain(pa_stream *s, pa_stream_success_cb_t cb, void *userdata);
 
 /** Get the playback latency of a stream */
-pa_operation* pa_stream_get_latency_info(pa_stream *p, void (*cb)(pa_stream *p, const pa_latency_info *i, void *userdata), void *userdata);
+pa_operation* pa_stream_get_latency_info(pa_stream *p, pa_stream_get_latency_info_cb_t cby, void *userdata);
 
 /** Set the callback function that is called whenever the state of the stream changes */
-void pa_stream_set_state_callback(pa_stream *s, void (*cb)(pa_stream *s, void *userdata), void *userdata);
+void pa_stream_set_state_callback(pa_stream *s, pa_stream_notify_cb_t cb, void *userdata);
 
 /** Set the callback function that is called when new data may be
  * written to the stream. */
-void pa_stream_set_write_callback(pa_stream *p, void (*cb)(pa_stream *p, size_t length, void *userdata), void *userdata);
+void pa_stream_set_write_callback(pa_stream *p, pa_stream_request_cb_t cb, void *userdata);
 
 /** Set the callback function that is called when new data is available from the stream.
- * Return the number of bytes read. \since 0.8
- */
-void pa_stream_set_read_callback(pa_stream *p, void (*cb)(pa_stream *p, size_t length, void *userdata), void *userdata);
+ * Return the number of bytes read. \since 0.8 */
+void pa_stream_set_read_callback(pa_stream *p, pa_stream_request_cb_t cb, void *userdata);
+
+/** Set the callback function that is called when a buffer overflow happens. (Only for playback streams) \since 0.8 */
+void pa_stream_set_overflow_callback(pa_stream *p, pa_stream_notify_cb_t cb, void *userdata);
+
+/** Set the callback function that is called when a buffer underflow happens. (Only for playback streams) \since 0.8 */
+void pa_stream_set_underflow_callback(pa_stream *p, pa_stream_notify_cb_t cb, void *userdata);
 
 /** Pause (or resume) playback of this stream temporarily. Available on both playback and recording streams. \since 0.3 */
-pa_operation* pa_stream_cork(pa_stream *s, int b, void (*cb) (pa_stream*s, int success, void *userdata), void *userdata);
+pa_operation* pa_stream_cork(pa_stream *s, int b, pa_stream_success_cb_t cb, void *userdata);
 
 /** Flush the playback buffer of this stream. Most of the time you're
  * better off using the parameter delta of pa_stream_write() instead of this
  * function. Available on both playback and recording streams. \since 0.3 */
-pa_operation* pa_stream_flush(pa_stream *s, void (*cb)(pa_stream *s, int success, void *userdata), void *userdata);
+pa_operation* pa_stream_flush(pa_stream *s, pa_stream_success_cb_t cb, void *userdata);
 
-/** Reenable prebuffering. Available for playback streams only. \since 0.6 */
-pa_operation* pa_stream_prebuf(pa_stream *s, void (*cb)(pa_stream *s, int success, void *userdata), void *userdata);
+/** Reenable prebuffering as specified in the pa_buffer_attr
+ * structure. Available for playback streams only. \since 0.6 */
+pa_operation* pa_stream_prebuf(pa_stream *s, pa_stream_success_cb_t cb, void *userdata);
 
 /** Request immediate start of playback on this stream. This disables
- * prebuffering as specified in the pa_buffer_attr structure. Available for playback streams only. \since
- * 0.3 */
-pa_operation* pa_stream_trigger(pa_stream *s, void (*cb)(pa_stream *s, int success, void *userdata), void *userdata);
+ * prebuffering as specified in the pa_buffer_attr
+ * structure, temporarily. Available for playback streams only. \since 0.3 */
+pa_operation* pa_stream_trigger(pa_stream *s, pa_stream_success_cb_t cb, void *userdata);
 
 /** Rename the stream. \since 0.5 */
-pa_operation* pa_stream_set_name(pa_stream *s, const char *name, void(*cb)(pa_stream*c, int success,  void *userdata), void *userdata);
+pa_operation* pa_stream_set_name(pa_stream *s, const char *name, pa_stream_success_cb_t cb, void *userdata);
 
 /** Return the total number of bytes written to/read from the
  * stream. This counter is not reset on pa_stream_flush(), you may do
diff --git a/src/polyp/subscribe.c b/src/polyp/subscribe.c
index b90e0bf..4e00997 100644
--- a/src/polyp/subscribe.c
+++ b/src/polyp/subscribe.c
@@ -44,7 +44,7 @@ void pa_command_subscribe_event(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSE
     if (pa_tagstruct_getu32(t, &e) < 0 ||
         pa_tagstruct_getu32(t, &index) < 0 ||
         !pa_tagstruct_eof(t)) {
-        pa_context_fail(c, PA_ERROR_PROTOCOL);
+        pa_context_fail(c, PA_ERR_PROTOCOL);
         goto finish;
     }
 
diff --git a/src/polypcore/iochannel.c b/src/polypcore/iochannel.c
index 7fd0915..c33f593 100644
--- a/src/polypcore/iochannel.c
+++ b/src/polypcore/iochannel.c
@@ -59,17 +59,17 @@ static void enable_mainloop_sources(pa_iochannel *io) {
         pa_io_event_flags_t f = PA_IO_EVENT_NULL;
         assert(io->input_event);
         
-        if (!io->readable)
+        if (!pa_iochannel_is_readable(io))
             f |= PA_IO_EVENT_INPUT;
-        if (!io->writable)
+        if (!pa_iochannel_is_writable(io))
             f |= PA_IO_EVENT_OUTPUT;
 
         io->mainloop->io_enable(io->input_event, f);
     } else {
         if (io->input_event)
-            io->mainloop->io_enable(io->input_event, io->readable ? PA_IO_EVENT_NULL : PA_IO_EVENT_INPUT);
+            io->mainloop->io_enable(io->input_event, pa_iochannel_is_readable(io) ? PA_IO_EVENT_NULL : PA_IO_EVENT_INPUT);
         if (io->output_event)
-            io->mainloop->io_enable(io->output_event, io->writable ? PA_IO_EVENT_NULL : PA_IO_EVENT_OUTPUT);
+            io->mainloop->io_enable(io->output_event, pa_iochannel_is_writable(io) ? PA_IO_EVENT_NULL : PA_IO_EVENT_OUTPUT);
     }
 }
 
@@ -82,33 +82,21 @@ static void callback(pa_mainloop_api* m, pa_io_event *e, int fd, pa_io_event_fla
     assert(fd >= 0);
     assert(userdata);
 
-    if ((f & (PA_IO_EVENT_HANGUP|PA_IO_EVENT_ERROR)) && !io->hungup) {
+    if ((f & (PA_IO_EVENT_HANGUP|PA_IO_EVENT_ERROR)) & !io->hungup) {
         io->hungup = 1;
         changed = 1;
+    }
 
-        if (e == io->input_event) {
-            io->mainloop->io_free(io->input_event);
-            io->input_event = NULL;
-
-            if (io->output_event == e)
-                io->output_event = NULL;
-        } else if (e == io->output_event) {
-            io->mainloop->io_free(io->output_event);
-            io->output_event = NULL;
-        }
-    } else {
-
-        if ((f & PA_IO_EVENT_INPUT) && !io->readable) {
-            io->readable = 1;
-            changed = 1;
-            assert(e == io->input_event);
-        }
-        
-        if ((f & PA_IO_EVENT_OUTPUT) && !io->writable) {
-            io->writable = 1;
-            changed = 1;
-            assert(e == io->output_event);
-        }
+    if ((f & PA_IO_EVENT_INPUT) && !io->readable) {
+        io->readable = 1;
+        changed = 1;
+        assert(e == io->input_event);
+    }
+    
+    if ((f & PA_IO_EVENT_OUTPUT) && !io->writable) {
+        io->writable = 1;
+        changed = 1;
+        assert(e == io->output_event);
     }
 
     if (changed) {
@@ -217,6 +205,7 @@ ssize_t pa_iochannel_write(pa_iochannel*io, const void*data, size_t l) {
     if (r < 0)
 #endif
         r = write(io->ofd, data, l);
+
     if (r >= 0) {
         io->writable = 0;
         enable_mainloop_sources(io);
diff --git a/src/polypcore/llist.h b/src/polypcore/llist.h
index eb8cd01..c54742d 100644
--- a/src/polypcore/llist.h
+++ b/src/polypcore/llist.h
@@ -66,4 +66,14 @@
                                     _item->next = _item->prev = NULL; \
                                     } while(0)
 
+#define PA_LLIST_FIND_HEAD(t,item,head) \
+do { \
+    t **_head = (head), *_item = (item); \
+    *_head = _item; \
+    assert(_head); \
+    while ((*_head)->prev) \
+        *_head = (*_head)->prev; \
+} while (0) \
+
+
 #endif
diff --git a/src/polypcore/mcalign.c b/src/polypcore/mcalign.c
index 0f229e2..f90fd7e 100644
--- a/src/polypcore/mcalign.c
+++ b/src/polypcore/mcalign.c
@@ -43,6 +43,7 @@ pa_mcalign *pa_mcalign_new(size_t base, pa_memblock_stat *s) {
     assert(base);
 
     m = pa_xnew(pa_mcalign, 1);
+    
     m->base = base;
     pa_memchunk_reset(&m->leftover);
     pa_memchunk_reset(&m->current);
@@ -64,11 +65,16 @@ void pa_mcalign_free(pa_mcalign *m) {
 }
 
 void pa_mcalign_push(pa_mcalign *m, const pa_memchunk *c) {
-    assert(m && c && c->memblock && c->length);
+    assert(m);
+    assert(c);
+    
+    assert(c->memblock);
+    assert(c->length > 0);
+
+    assert(!m->current.memblock);
     
     /* Append to the leftover memory block */
     if (m->leftover.memblock) {
-        assert(!m->current.memblock);
         
         /* Try to merge */
         if (m->leftover.memblock == c->memblock &&
@@ -110,8 +116,6 @@ void pa_mcalign_push(pa_mcalign *m, const pa_memchunk *c) {
             }
         }
     } else {
-        assert(!m->leftover.memblock && !m->current.memblock);
-
         /* Nothing to merge or copy, just store it */
         
         if (c->length >= m->base)
@@ -124,7 +128,8 @@ void pa_mcalign_push(pa_mcalign *m, const pa_memchunk *c) {
 }
 
 int pa_mcalign_pop(pa_mcalign *m, pa_memchunk *c) {
-    assert(m && c);
+    assert(m);
+    assert(c);
 
     /* First test if there's a leftover memory block available */
     if (m->leftover.memblock) {
@@ -187,3 +192,15 @@ int pa_mcalign_pop(pa_mcalign *m, pa_memchunk *c) {
     return -1;
     
 }
+
+size_t pa_mcalign_csize(pa_mcalign *m, size_t l) {
+    assert(m);
+    assert(l > 0);
+
+    assert(!m->current.memblock);
+           
+    if (m->leftover.memblock)
+        l += m->leftover.length;
+    
+    return (l/m->base)*m->base;
+}
diff --git a/src/polypcore/mcalign.h b/src/polypcore/mcalign.h
index a9107e0..5801946 100644
--- a/src/polypcore/mcalign.h
+++ b/src/polypcore/mcalign.h
@@ -74,4 +74,7 @@ void pa_mcalign_push(pa_mcalign *m, const pa_memchunk *c);
  * nonzero otherwise. */
 int pa_mcalign_pop(pa_mcalign *m, pa_memchunk *c);
 
+/* If we pass l bytes in now, how many bytes would we get out? */
+size_t pa_mcalign_csize(pa_mcalign *m, size_t l);
+
 #endif
diff --git a/src/polypcore/memblock.c b/src/polypcore/memblock.c
index 2c0bef5..04e8436 100644
--- a/src/polypcore/memblock.c
+++ b/src/polypcore/memblock.c
@@ -111,13 +111,16 @@ pa_memblock *pa_memblock_new_user(void *d, size_t length, void (*free_cb)(void *
 }
 
 pa_memblock* pa_memblock_ref(pa_memblock*b) {
-    assert(b && b->ref >= 1);
+    assert(b);
+    assert(b->ref >= 1);
+    
     b->ref++;
     return b;
 }
 
 void pa_memblock_unref(pa_memblock*b) {
-    assert(b && b->ref >= 1);
+    assert(b);
+    assert(b->ref >= 1);
 
     if ((--(b->ref)) == 0) {
         stat_remove(b);
diff --git a/src/polypcore/memblock.h b/src/polypcore/memblock.h
index c575140..9471278 100644
--- a/src/polypcore/memblock.h
+++ b/src/polypcore/memblock.h
@@ -79,7 +79,6 @@ references to the memory. This causes the memory to be copied and
 converted into a PA_MEMBLOCK_DYNAMIC type memory block */
 void pa_memblock_unref_fixed(pa_memblock*b);
 
-
 pa_memblock_stat* pa_memblock_stat_new(void);
 void pa_memblock_stat_unref(pa_memblock_stat *s);
 pa_memblock_stat * pa_memblock_stat_ref(pa_memblock_stat *s);
diff --git a/src/polypcore/memblockq.c b/src/polypcore/memblockq.c
index 4a0225e..05c810b 100644
--- a/src/polypcore/memblockq.c
+++ b/src/polypcore/memblockq.c
@@ -38,30 +38,45 @@
 
 struct memblock_list {
     struct memblock_list *next, *prev;
+    int64_t index;
     pa_memchunk chunk;
 };
 
 struct pa_memblockq {
     struct memblock_list *blocks, *blocks_tail;
     unsigned n_blocks;
-    size_t current_length, maxlength, tlength, base, prebuf, orig_prebuf, minreq;
-    pa_mcalign *mcalign;
+    size_t maxlength, tlength, base, prebuf, minreq;
+    int64_t read_index, write_index;
+    enum { PREBUF, RUNNING } state;
     pa_memblock_stat *memblock_stat;
+    pa_memblock *silence;
+    pa_mcalign *mcalign;
 };
 
-pa_memblockq* pa_memblockq_new(size_t maxlength, size_t tlength, size_t base, size_t prebuf, size_t minreq, pa_memblock_stat *s) {
+pa_memblockq* pa_memblockq_new(
+        int64_t idx,
+        size_t maxlength,
+        size_t tlength,
+        size_t base,
+        size_t prebuf,
+        size_t minreq,
+        pa_memblock *silence,
+        pa_memblock_stat *s) {
+    
     pa_memblockq* bq;
-    assert(maxlength && base && maxlength);
     
-    bq = pa_xmalloc(sizeof(pa_memblockq));
-    bq->blocks = bq->blocks_tail = 0;
+    assert(base > 0);
+    assert(maxlength >= base);
+    
+    bq = pa_xnew(pa_memblockq, 1);
+    bq->blocks = bq->blocks_tail = NULL;
     bq->n_blocks = 0;
 
-    bq->current_length = 0;
+    bq->base = base;
+    bq->read_index = bq->write_index = idx;
+    bq->memblock_stat = s;
 
     pa_log_debug(__FILE__": memblockq requested: maxlength=%u, tlength=%u, base=%u, prebuf=%u, minreq=%u\n", maxlength, tlength, base, prebuf, minreq);
-    
-    bq->base = base;
 
     bq->maxlength = ((maxlength+base-1)/base)*base;
     assert(bq->maxlength >= base);
@@ -70,26 +85,25 @@ pa_memblockq* pa_memblockq_new(size_t maxlength, size_t tlength, size_t base, si
     if (!bq->tlength || bq->tlength >= bq->maxlength)
         bq->tlength = bq->maxlength;
 
-    bq->minreq = (minreq/base)*base;
-    if (bq->minreq == 0)
-        bq->minreq = 1;
-    
-    bq->prebuf = (prebuf == (size_t) -1) ? bq->maxlength/2 : prebuf;
-    bq->prebuf = (bq->prebuf/base)*base;
+    bq->prebuf = (prebuf == (size_t) -1) ? bq->tlength/2 : prebuf;
+    bq->prebuf = ((bq->prebuf+base-1)/base)*base;
     if (bq->prebuf > bq->maxlength)
         bq->prebuf = bq->maxlength;
 
-    if (bq->prebuf > bq->tlength - bq->minreq)
-        bq->prebuf = bq->tlength - bq->minreq;
+    bq->minreq = (minreq/base)*base;
+    
+    if (bq->minreq > bq->tlength - bq->prebuf)
+        bq->minreq = bq->tlength - bq->prebuf;
 
-    bq->orig_prebuf = bq->prebuf;
+    if (!bq->minreq)
+        bq->minreq = 1;
     
     pa_log_debug(__FILE__": memblockq sanitized: maxlength=%u, tlength=%u, base=%u, prebuf=%u, minreq=%u\n", bq->maxlength, bq->tlength, bq->base, bq->prebuf, bq->minreq);
-    
-    bq->mcalign = NULL;
-
-    bq->memblock_stat = s;
 
+    bq->state = bq->prebuf ? PREBUF : RUNNING;
+    bq->silence = silence ? pa_memblock_ref(silence) : NULL;
+    bq->mcalign = NULL;
+    
     return bq;
 }
 
@@ -97,248 +111,510 @@ void pa_memblockq_free(pa_memblockq* bq) {
     assert(bq);
 
     pa_memblockq_flush(bq);
-    
+
+    if (bq->silence)
+        pa_memblock_unref(bq->silence);
+
     if (bq->mcalign)
         pa_mcalign_free(bq->mcalign);
-
+    
     pa_xfree(bq);
 }
 
-void pa_memblockq_push(pa_memblockq* bq, const pa_memchunk *chunk, size_t delta) {
-    struct memblock_list *q;
-    assert(bq && chunk && chunk->memblock && chunk->length && (chunk->length % bq->base) == 0);
-
-    pa_memblockq_seek(bq, delta);
-    
-    if (bq->blocks_tail && bq->blocks_tail->chunk.memblock == chunk->memblock) {
-        /* Try to merge memory chunks */
+static void drop_block(pa_memblockq *bq, struct memblock_list *q) {
+    assert(bq);
+    assert(q);
 
-        if (bq->blocks_tail->chunk.index+bq->blocks_tail->chunk.length == chunk->index) {
-            bq->blocks_tail->chunk.length += chunk->length;
-            bq->current_length += chunk->length;
-            return;
-        }
-    }
+    assert(bq->n_blocks >= 1);
     
-    q = pa_xmalloc(sizeof(struct memblock_list));
-
-    q->chunk = *chunk;
-    pa_memblock_ref(q->chunk.memblock);
-    assert(q->chunk.index+q->chunk.length <= q->chunk.memblock->length);
-    q->next = NULL;
-    if ((q->prev = bq->blocks_tail))
-        bq->blocks_tail->next = q;
+    if (q->prev)
+        q->prev->next = q->next;
     else
-        bq->blocks = q;
+        bq->blocks = q->next;
     
-    bq->blocks_tail = q;
+    if (q->next)
+        q->next->prev = q->prev;
+    else
+        bq->blocks_tail = q->prev;
 
-    bq->n_blocks++;
-    bq->current_length += chunk->length;
+    pa_memblock_unref(q->chunk.memblock);
+    pa_xfree(q);
 
-    pa_memblockq_shorten(bq, bq->maxlength);
+    bq->n_blocks--;
 }
 
-int pa_memblockq_peek(pa_memblockq* bq, pa_memchunk *chunk) {
-    assert(bq && chunk);
+static int can_push(pa_memblockq *bq, size_t l) {
+    int64_t end;
 
-    if (!bq->blocks || bq->current_length < bq->prebuf)
-        return -1;
+    assert(bq);
 
-    bq->prebuf = 0;
+    if (bq->read_index > bq->write_index) {
+        int64_t d =  bq->read_index - bq->write_index;
 
-    *chunk = bq->blocks->chunk;
-    pa_memblock_ref(chunk->memblock);
+        if (l > d)
+            l -= d;
+        else
+            return 1;
+    }
 
-    return 0;
+    end = bq->blocks_tail ? bq->blocks_tail->index + bq->blocks_tail->chunk.length : 0;
+
+    /* Make sure that the list doesn't get too long */
+    if (bq->write_index + l > end)
+        if (bq->write_index + l - bq->read_index > bq->maxlength)
+            return 0;
+
+    return 1;
 }
 
-void pa_memblockq_drop(pa_memblockq *bq, const pa_memchunk *chunk, size_t length) {
-    assert(bq && chunk && length);
+int pa_memblockq_push(pa_memblockq* bq, const pa_memchunk *uchunk) {
+    
+    struct memblock_list *q, *n;
+    pa_memchunk chunk;
+    
+    assert(bq);
+    assert(uchunk);
+    assert(uchunk->memblock);
+    assert(uchunk->length > 0);
+    assert(uchunk->index + uchunk->length <= uchunk->memblock->length);
+
+    if (uchunk->length % bq->base)
+        return -1;
+
+    if (!can_push(bq, uchunk->length))
+        return -1;
 
-    if (!bq->blocks || memcmp(&bq->blocks->chunk, chunk, sizeof(pa_memchunk))) 
-        return;
+    chunk = *uchunk;
     
-    assert(length <= bq->blocks->chunk.length);
-    pa_memblockq_skip(bq, length);
-}
+    if (bq->read_index > bq->write_index) {
 
-static void remove_block(pa_memblockq *bq, struct memblock_list *q) {
-    assert(bq && q);
+        /* We currently have a buffer underflow, we need to drop some
+         * incoming data */
 
-    if (q->prev)
-        q->prev->next = q->next;
-    else {
-        assert(bq->blocks == q);
-        bq->blocks = q->next;
+        int64_t d = bq->read_index - bq->write_index;
+
+        if (chunk.length > d) {
+            chunk.index += d;
+            chunk.length -= d;
+            bq->write_index = bq->read_index;
+        } else {
+            /* We drop the incoming data completely */
+            bq->write_index += chunk.length;
+            return 0;
+        }
     }
     
-    if (q->next)
-        q->next->prev = q->prev;
-    else {
-        assert(bq->blocks_tail == q);
-        bq->blocks_tail = q->prev;
+    /* We go from back to front to look for the right place to add
+     * this new entry. Drop data we will overwrite on the way */
+
+    q = bq->blocks_tail;
+    while (q) {
+
+        if (bq->write_index >= q->index + q->chunk.length)
+            /* We found the entry where we need to place the new entry immediately after */
+            break;
+        else if (bq->write_index + chunk.length <= q->index) {
+            /* This entry isn't touched at all, let's skip it */
+            q = q->prev;
+        } else if (bq->write_index <= q->index &&
+            bq->write_index + chunk.length >= q->index + q->chunk.length) {
+
+            /* This entry is fully replaced by the new entry, so let's drop it */
+
+            struct memblock_list *p;
+            p = q;
+            q = q->prev;
+            drop_block(bq, p);
+        } else if (bq->write_index >= q->index) {
+            /* The write index points into this memblock, so let's
+             * truncate or split it */
+
+            if (bq->write_index + chunk.length < q->index + q->chunk.length) {
+
+                /* We need to save the end of this memchunk */
+                struct memblock_list *p;
+                size_t d;
+
+                /* Create a new list entry for the end of thie memchunk */
+                p = pa_xnew(struct memblock_list, 1);
+                p->chunk = q->chunk;
+                pa_memblock_ref(p->chunk.memblock);
+
+                /* Calculate offset */
+                d = bq->write_index + chunk.length - q->index;
+                assert(d > 0);
+
+                /* Drop it from the new entry */
+                p->index = q->index + d;
+                p->chunk.length -= d;
+
+                /* Add it to the list */
+                p->prev = q;
+                if ((p->next = q->next))
+                    q->next->prev = p;
+                else
+                    bq->blocks_tail = p;
+                q->next = p;
+
+                bq->n_blocks++;
+            }
+
+            /* Truncate the chunk */
+            if (!(q->chunk.length = bq->write_index - q->index)) {
+                struct memblock_list *p;
+                p = q;
+                q = q->prev;
+                drop_block(bq, p);
+            }
+
+            /* We had to truncate this block, hence we're now at the right position */
+            break;
+        } else {
+            size_t d;
+
+            assert(bq->write_index + chunk.length > q->index &&
+                   bq->write_index + chunk.length < q->index + q->chunk.length &&
+                   bq->write_index < q->index);
+            
+            /* The job overwrites the current entry at the end, so let's drop the beginning of this entry */
+
+            d = bq->write_index + chunk.length - q->index;
+            q->index += d;
+            q->chunk.index += d;
+            q->chunk.length -= d;
+            
+            q = q->prev;
+        }
+        
     }
+
+    if (q) {
+        assert(bq->write_index >=  q->index + q->chunk.length);
+        assert(!q->next || (bq->write_index+chunk.length <= q->next->index));
+               
+        /* Try to merge memory blocks */
+        
+        if (q->chunk.memblock == chunk.memblock &&
+            q->chunk.index + q->chunk.length == chunk.index &&
+            bq->write_index == q->index + q->chunk.length) {
+            
+            q->chunk.length += chunk.length;
+            bq->write_index += chunk.length;
+            return 0;
+        }
+    } else
+        assert(!bq->blocks || (bq->write_index+chunk.length <= bq->blocks->index));
+
+
+    n = pa_xnew(struct memblock_list, 1);
+    n->chunk = chunk;
+    pa_memblock_ref(n->chunk.memblock);
+    n->index = bq->write_index;
+    bq->write_index += n->chunk.length;
+
+    n->next = q ? q->next : bq->blocks;
+    n->prev = q;
+
+    if (n->next)
+        n->next->prev = n;
+    else
+        bq->blocks_tail = n;
+
+    if (n->prev)
+        n->prev->next = n;
+    else
+        bq->blocks = n;
     
-    pa_memblock_unref(q->chunk.memblock);
-    pa_xfree(q);
-    
-    bq->n_blocks--;
+    bq->n_blocks++;
+    return 0;
 }
 
-void pa_memblockq_skip(pa_memblockq *bq, size_t length) {
-    assert(bq && length && (length % bq->base) == 0);
+int pa_memblockq_peek(pa_memblockq* bq, pa_memchunk *chunk) {
+    assert(bq);
+    assert(chunk);
 
-    while (length > 0) {
-        size_t l = length;
-        assert(bq->blocks && bq->current_length >= length);
-        
-        if (l > bq->blocks->chunk.length)
-            l = bq->blocks->chunk.length;
+    if (bq->state == PREBUF) {
 
-        bq->blocks->chunk.index += l;
-        bq->blocks->chunk.length -= l;
-        bq->current_length -= l;
-        
-        if (!bq->blocks->chunk.length)
-            remove_block(bq, bq->blocks);
+        /* We need to pre-buffer */
+        if (pa_memblockq_get_length(bq) < bq->prebuf)
+            return -1;
+
+        bq->state = RUNNING;
 
-        length -= l;
+    } else if (bq->prebuf > 0 && bq->read_index >= bq->write_index) {
+
+        /* Buffer underflow protection */
+        bq->state = PREBUF;
+        return -1;
     }
-}
+    
+    /* Do we need to spit out silence? */
+    if (!bq->blocks || bq->blocks->index > bq->read_index) {
 
-void pa_memblockq_shorten(pa_memblockq *bq, size_t length) {
-    size_t l;
-    assert(bq);
+        size_t length;
+
+        /* How much silence shall we return? */
+        length = bq->blocks ? bq->blocks->index - bq->read_index : 0;
+
+        /* We need to return silence, since no data is yet available */
+        if (bq->silence) {
+            chunk->memblock = pa_memblock_ref(bq->silence);
 
-    if (bq->current_length <= length)
-        return;
+            if (!length || length > chunk->memblock->length)
+                length = chunk->memblock->length;
+                
+            chunk->length = length;
+        } else {
+            chunk->memblock = NULL;
+            chunk->length = length;
+        }
+
+        chunk->index = 0;
+        return 0;
+    }
 
-    /*pa_log(__FILE__": Warning! pa_memblockq_shorten()\n");*/
+    /* Ok, let's pass real data to the caller */
+    assert(bq->blocks->index == bq->read_index);
     
-    l = bq->current_length - length;
-    l /= bq->base;
-    l *= bq->base;
+    *chunk = bq->blocks->chunk;
+    pa_memblock_ref(chunk->memblock);
 
-    pa_memblockq_skip(bq, l);
+    return 0;
 }
 
-
-void pa_memblockq_empty(pa_memblockq *bq) {
+void pa_memblockq_drop(pa_memblockq *bq, const pa_memchunk *chunk, size_t length) {
     assert(bq);
-    pa_memblockq_shorten(bq, 0);
+    assert(length % bq->base == 0);
+
+    assert(!chunk || length <= chunk->length);
+
+    if (chunk) {
+
+        if (bq->blocks && bq->blocks->index == bq->read_index) {
+            /* The first item in queue is valid */
+
+            /* Does the chunk match with what the user supplied us? */
+            if (memcmp(chunk, &bq->blocks->chunk, sizeof(pa_memchunk)) != 0)
+                return;
+
+        } else {
+            size_t l;
+
+            /* The first item in the queue is not yet relevant */
+
+            assert(!bq->blocks || bq->blocks->index > bq->read_index);
+            l = bq->blocks ? bq->blocks->index - bq->read_index : 0;
+
+            if (bq->silence) {
+
+                if (!l || l > bq->silence->length)
+                    l = bq->silence->length;
+
+            }
+
+            /* Do the entries still match? */
+            if (chunk->index != 0 || chunk->length != l || chunk->memblock != bq->silence)
+                return;
+        }
+    }
+
+    while (length > 0) {
+
+        if (bq->blocks) {
+            size_t d;
+
+            assert(bq->blocks->index >= bq->read_index);
+
+            d = (size_t) (bq->blocks->index - bq->read_index);
+            
+            if (d >= length) {
+                /* The first block is too far in the future */
+                
+                bq->read_index += length;
+                break;
+            } else {
+                
+                length -= d;
+                bq->read_index += d;
+            }
+
+            assert(bq->blocks->index == bq->read_index);
+
+            if (bq->blocks->chunk.length <= length) {
+                /* We need to drop the full block */
+
+                length -= bq->blocks->chunk.length;
+                bq->read_index += bq->blocks->chunk.length;
+
+                drop_block(bq, bq->blocks);
+            } else {
+                /* Only the start of this block needs to be dropped */
+
+                bq->blocks->chunk.index += length;
+                bq->blocks->chunk.length -= length;
+                bq->blocks->index += length;
+                bq->read_index += length;
+                break;
+            }
+            
+        } else {
+
+            /* The list is empty, there's nothing we could drop */
+            bq->read_index += length;
+            break;
+        }
+    }
 }
 
 int pa_memblockq_is_readable(pa_memblockq *bq) {
     assert(bq);
 
-    return bq->current_length && (bq->current_length >= bq->prebuf);
+    if (bq->prebuf > 0) {
+        size_t l = pa_memblockq_get_length(bq);
+        
+        if (bq->state == PREBUF && l < bq->prebuf)
+            return 0;
+
+        if (l <= 0)
+            return 0;
+    }
+
+    return 1;
 }
 
 int pa_memblockq_is_writable(pa_memblockq *bq, size_t length) {
     assert(bq);
 
-    return bq->current_length + length <= bq->tlength;
+    if (length % bq->base)
+        return 0;
+    
+    return pa_memblockq_get_length(bq) + length <= bq->tlength;
 }
 
-uint32_t pa_memblockq_get_length(pa_memblockq *bq) {
+size_t pa_memblockq_get_length(pa_memblockq *bq) {
     assert(bq);
-    return bq->current_length;
+
+    if (bq->write_index <= bq->read_index)
+        return 0;
+    
+    return (size_t) (bq->write_index - bq->read_index);
 }
 
-uint32_t pa_memblockq_missing(pa_memblockq *bq) {
+size_t pa_memblockq_missing(pa_memblockq *bq) {
     size_t l;
     assert(bq);
 
-    if (bq->current_length >= bq->tlength)
+    if ((l = pa_memblockq_get_length(bq)) >= bq->tlength)
         return 0;
 
-    l = bq->tlength - bq->current_length;
-    assert(l);
-
+    l = bq->tlength - l;
     return (l >= bq->minreq) ? l : 0;
 }
 
-void pa_memblockq_push_align(pa_memblockq* bq, const pa_memchunk *chunk, size_t delta) {
-    pa_memchunk rchunk;
-    assert(bq && chunk && bq->base);
+size_t pa_memblockq_get_minreq(pa_memblockq *bq) {
+    assert(bq);
 
-    if (bq->base == 1) {
-        pa_memblockq_push(bq, chunk, delta);
-        return;
-    }
+    return bq->minreq;
+}
 
-    if (!bq->mcalign) {
-        bq->mcalign = pa_mcalign_new(bq->base, bq->memblock_stat);
-        assert(bq->mcalign);
+void pa_memblockq_seek(pa_memblockq *bq, int64_t offset, pa_seek_mode_t seek) {
+    assert(bq);
+
+    switch (seek) {
+        case PA_SEEK_RELATIVE:
+            bq->write_index += offset;
+            return;
+        case PA_SEEK_ABSOLUTE:
+            bq->write_index = offset;
+            return;
+        case PA_SEEK_RELATIVE_ON_READ:
+            bq->write_index = bq->read_index + offset;
+            return;
+        case PA_SEEK_RELATIVE_END:
+            bq->write_index = (bq->blocks_tail ? bq->blocks_tail->index + bq->blocks_tail->chunk.length : bq->read_index) + offset;
+            return;
     }
+
+    assert(0);
+}
+
+void pa_memblockq_flush(pa_memblockq *bq) {
+    assert(bq);
     
-    pa_mcalign_push(bq->mcalign, chunk);
+    while (bq->blocks)
+        drop_block(bq, bq->blocks);
 
-    while (pa_mcalign_pop(bq->mcalign, &rchunk) >= 0) {
-        pa_memblockq_push(bq, &rchunk, delta);
-        pa_memblock_unref(rchunk.memblock);
-        delta = 0;
-    }
+    assert(bq->n_blocks == 0);
+    bq->write_index = bq->read_index;
+
+    pa_memblockq_prebuf_force(bq);
 }
 
-uint32_t pa_memblockq_get_minreq(pa_memblockq *bq) {
+size_t pa_memblockq_get_tlength(pa_memblockq *bq) {
     assert(bq);
-    return bq->minreq;
+    
+    return bq->tlength;
 }
 
-void pa_memblockq_prebuf_disable(pa_memblockq *bq) {
+int64_t pa_memblockq_get_read_index(pa_memblockq *bq) {
     assert(bq);
-    bq->prebuf = 0;
+    return bq->read_index;
 }
 
-void pa_memblockq_prebuf_reenable(pa_memblockq *bq) {
+int64_t pa_memblockq_get_write_index(pa_memblockq *bq) {
     assert(bq);
-    bq->prebuf = bq->orig_prebuf;
+    return bq->write_index;
 }
 
-void pa_memblockq_seek(pa_memblockq *bq, size_t length) {
+int pa_memblockq_push_align(pa_memblockq* bq, const pa_memchunk *chunk) {
+    pa_memchunk rchunk;
+
     assert(bq);
+    assert(chunk && bq->base);
+ 	
+    if (bq->base == 1)
+        return pa_memblockq_push(bq, chunk);
+ 	
+    if (!bq->mcalign)
+        bq->mcalign = pa_mcalign_new(bq->base, bq->memblock_stat);
 
-    if (!length)
-        return;
+    if (!can_push(bq, pa_mcalign_csize(bq->mcalign, chunk->length)))
+        return -1;
+    
+    pa_mcalign_push(bq->mcalign, chunk);
+ 	
+    while (pa_mcalign_pop(bq->mcalign, &rchunk) >= 0) {
+        int r;
+        r = pa_memblockq_push(bq, &rchunk);
+        pa_memblock_unref(rchunk.memblock);
 
-    while (length >= bq->base) {
-        size_t l = length;
-        if (!bq->current_length)
-            return;
+        if (r < 0)
+            return -1;
+    }
 
-        assert(bq->blocks_tail);
-        
-        if (l > bq->blocks_tail->chunk.length)
-            l = bq->blocks_tail->chunk.length;
+    return 0;
+}
 
-        bq->blocks_tail->chunk.length -= l;
-        bq->current_length -= l;
-        
-        if (bq->blocks_tail->chunk.length == 0)
-            remove_block(bq, bq->blocks);
+void pa_memblockq_shorten(pa_memblockq *bq, size_t length) {
+    size_t l;
+    assert(bq);
 
-        length -= l;
-    }
+    l = pa_memblockq_get_length(bq);
+
+    if (l > length)
+        pa_memblockq_drop(bq, NULL, l - length);
 }
 
-void pa_memblockq_flush(pa_memblockq *bq) {
-    struct memblock_list *l;
+void pa_memblockq_prebuf_disable(pa_memblockq *bq) {
     assert(bq);
-    
-    while ((l = bq->blocks)) {
-        bq->blocks = l->next;
-        pa_memblock_unref(l->chunk.memblock);
-        pa_xfree(l);
-    }
 
-    bq->blocks_tail = NULL;
-    bq->n_blocks = 0;
-    bq->current_length = 0;
+    if (bq->state == PREBUF)
+        bq->state = RUNNING;
 }
 
-uint32_t pa_memblockq_get_tlength(pa_memblockq *bq) {
+void pa_memblockq_prebuf_force(pa_memblockq *bq) {
     assert(bq);
-    return bq->tlength;
+
+    if (bq->state == RUNNING && bq->prebuf > 0)
+        bq->state = PREBUF;
 }
diff --git a/src/polypcore/memblockq.h b/src/polypcore/memblockq.h
index 7bb25f9..210f1a0 100644
--- a/src/polypcore/memblockq.h
+++ b/src/polypcore/memblockq.h
@@ -23,9 +23,11 @@
 ***/
 
 #include <sys/types.h>
+#include <inttypes.h>
 
 #include <polypcore/memblock.h>
 #include <polypcore/memchunk.h>
+#include <polyp/def.h>
 
 /* A memblockq is a queue of pa_memchunks (yepp, the name is not
  * perfect). It is similar to the ring buffers used by most other
@@ -35,42 +37,59 @@
 
 typedef struct pa_memblockq pa_memblockq;
 
+
 /* Parameters:
-   - maxlength: maximum length of queue. If more data is pushed into the queue, data from the front is dropped
-   - length:    the target length of the queue.
-   - base:      a base value for all metrics. Only multiples of this value are popped from the queue
-   - prebuf:    before passing the first byte out, make sure that enough bytes are in the queue
-   - minreq:    pa_memblockq_missing() will only return values greater than this value
+   
+   - idx:       start value for both read and write index
+
+   - maxlength: maximum length of queue. If more data is pushed into
+                the queue, the operation will fail. Must not be 0.
+   
+   - tlength:   the target length of the queue. Pass 0 for the default.
+   
+   - base:      a base value for all metrics. Only multiples of this value
+                are popped from the queue or should be pushed into
+                it. Must not be 0.
+   
+   - prebuf:    If the queue runs empty wait until this many bytes are in
+                queue again before passing the first byte out. If set
+                to 0 pa_memblockq_pop() will return a silence memblock
+                if no data is in the queue and will never fail. Pass
+                (size_t) -1 for the default.
+                
+   - minreq:    pa_memblockq_missing() will only return values greater
+                than this value. Pass 0 for the default.
+   
+   - silence:   return this memblock whzen reading unitialized data
 */
-pa_memblockq* pa_memblockq_new(size_t maxlength,
-                                      size_t tlength,
-                                      size_t base,
-                                      size_t prebuf,
-                                      size_t minreq,
-                                      pa_memblock_stat *s);
+pa_memblockq* pa_memblockq_new(
+        int64_t idx,
+        size_t maxlength,
+        size_t tlength,
+        size_t base,
+        size_t prebuf, 
+        size_t minreq,
+        pa_memblock *silence,
+        pa_memblock_stat *s);
+
 void pa_memblockq_free(pa_memblockq*bq);
 
-/* Push a new memory chunk into the queue. Optionally specify a value for future cancellation. */
-void pa_memblockq_push(pa_memblockq* bq, const pa_memchunk *chunk, size_t delta);
+/* Push a new memory chunk into the queue.  */
+int pa_memblockq_push(pa_memblockq* bq, const pa_memchunk *chunk);
 
-/* Same as pa_memblockq_push(), however chunks are filtered through a mcalign object, and thus aligned to multiples of base */
-void pa_memblockq_push_align(pa_memblockq* bq, const pa_memchunk *chunk, size_t delta);
+/* Push a new memory chunk into the queue, but filter it through a
+ * pa_mcalign object. Don't mix this with pa_memblockq_seek() unless
+ * you know what you do. */
+int pa_memblockq_push_align(pa_memblockq* bq, const pa_memchunk *chunk);
 
 /* Return a copy of the next memory chunk in the queue. It is not removed from the queue */
 int pa_memblockq_peek(pa_memblockq* bq, pa_memchunk *chunk);
 
-/* Drop the specified bytes from the queue, only valid aufter pa_memblockq_peek() */
+/* Drop the specified bytes from the queue, but only if the first
+ * chunk in the queue matches the one passed here. If NULL is passed,
+ * this check isn't done. */
 void pa_memblockq_drop(pa_memblockq *bq, const pa_memchunk *chunk, size_t length);
 
-/* Drop the specified bytes from the queue */
-void pa_memblockq_skip(pa_memblockq *bq, size_t length);
-
-/* Shorten the pa_memblockq to the specified length by dropping data at the end of the queue */
-void pa_memblockq_shorten(pa_memblockq *bq, size_t length);
-
-/* Empty the pa_memblockq */
-void pa_memblockq_empty(pa_memblockq *bq);
-
 /* Test if the pa_memblockq is currently readable, that is, more data than base */
 int pa_memblockq_is_readable(pa_memblockq *bq);
 
@@ -78,27 +97,38 @@ int pa_memblockq_is_readable(pa_memblockq *bq);
 int pa_memblockq_is_writable(pa_memblockq *bq, size_t length);
 
 /* Return the length of the queue in bytes */
-uint32_t pa_memblockq_get_length(pa_memblockq *bq);
+size_t pa_memblockq_get_length(pa_memblockq *bq);
 
 /* Return how many bytes are missing in queue to the specified fill amount */
-uint32_t pa_memblockq_missing(pa_memblockq *bq);
+size_t pa_memblockq_missing(pa_memblockq *bq);
 
 /* Returns the minimal request value */
-uint32_t pa_memblockq_get_minreq(pa_memblockq *bq);
-
-/* Force disabling of pre-buf even when the pre-buffer is not yet filled */
-void pa_memblockq_prebuf_disable(pa_memblockq *bq);
-
-/* Reenable pre-buf to the initial level */
-void pa_memblockq_prebuf_reenable(pa_memblockq *bq);
+size_t pa_memblockq_get_minreq(pa_memblockq *bq);
 
 /* Manipulate the write pointer */
-void pa_memblockq_seek(pa_memblockq *bq, size_t delta);
+void pa_memblockq_seek(pa_memblockq *bq, int64_t offset, pa_seek_mode_t seek);
 
-/* Flush the queue */
+/* Set the queue to silence, set write index to read index */
 void pa_memblockq_flush(pa_memblockq *bq);
 
 /* Get Target length */
 uint32_t pa_memblockq_get_tlength(pa_memblockq *bq);
 
+/* Return the current read index */
+int64_t pa_memblockq_get_read_index(pa_memblockq *bq);
+
+/* Return the current write index */
+int64_t pa_memblockq_get_write_index(pa_memblockq *bq);
+
+/* Shorten the pa_memblockq to the specified length by dropping data
+ * at the read end of the queue. The read index is increased until the
+ * queue has the specified length */
+void pa_memblockq_shorten(pa_memblockq *bq, size_t length);
+
+/* Ignore prebuf for now */
+void pa_memblockq_prebuf_disable(pa_memblockq *bq);
+
+/* Force prebuf */
+void pa_memblockq_prebuf_force(pa_memblockq *bq);
+
 #endif
diff --git a/src/polypcore/native-common.h b/src/polypcore/native-common.h
index ac3ea82..0d17b02 100644
--- a/src/polypcore/native-common.h
+++ b/src/polypcore/native-common.h
@@ -28,22 +28,22 @@
 PA_C_DECL_BEGIN
 
 enum {
+    /* Generic commands */
     PA_COMMAND_ERROR,
     PA_COMMAND_TIMEOUT, /* pseudo command */
     PA_COMMAND_REPLY,
+
+    /* Commands from client to server */
     PA_COMMAND_CREATE_PLAYBACK_STREAM,
     PA_COMMAND_DELETE_PLAYBACK_STREAM,
     PA_COMMAND_CREATE_RECORD_STREAM,
     PA_COMMAND_DELETE_RECORD_STREAM,
     PA_COMMAND_EXIT,
-    PA_COMMAND_REQUEST,
     PA_COMMAND_AUTH,
     PA_COMMAND_SET_CLIENT_NAME,
     PA_COMMAND_LOOKUP_SINK,
     PA_COMMAND_LOOKUP_SOURCE,
     PA_COMMAND_DRAIN_PLAYBACK_STREAM,
-    PA_COMMAND_PLAYBACK_STREAM_KILLED,
-    PA_COMMAND_RECORD_STREAM_KILLED,
     PA_COMMAND_STAT,
     PA_COMMAND_GET_PLAYBACK_LATENCY,
     PA_COMMAND_CREATE_UPLOAD_STREAM,
@@ -68,7 +68,6 @@ enum {
     PA_COMMAND_GET_SAMPLE_INFO,
     PA_COMMAND_GET_SAMPLE_INFO_LIST,
     PA_COMMAND_SUBSCRIBE,
-    PA_COMMAND_SUBSCRIBE_EVENT,
     
     PA_COMMAND_SET_SINK_VOLUME,
     PA_COMMAND_SET_SINK_INPUT_VOLUME,
@@ -95,6 +94,15 @@ enum {
     PA_COMMAND_CORK_RECORD_STREAM,
     PA_COMMAND_FLUSH_RECORD_STREAM,
     PA_COMMAND_PREBUF_PLAYBACK_STREAM,
+
+    /* Commands from server to client */
+    PA_COMMAND_REQUEST,
+    PA_COMMAND_OVERFLOW,
+    PA_COMMAND_UNDERFLOW,
+    PA_COMMAND_PLAYBACK_STREAM_KILLED,
+    PA_COMMAND_RECORD_STREAM_KILLED,
+    PA_COMMAND_SUBSCRIBE_EVENT,
+
     PA_COMMAND_MAX
 };
 
diff --git a/src/polypcore/packet.c b/src/polypcore/packet.c
index 41803cf..31ddad9 100644
--- a/src/polypcore/packet.c
+++ b/src/polypcore/packet.c
@@ -32,37 +32,46 @@
 
 pa_packet* pa_packet_new(size_t length) {
     pa_packet *p;
+
     assert(length);
+
     p = pa_xmalloc(sizeof(pa_packet)+length);
     p->ref = 1;
     p->length = length;
     p->data = (uint8_t*) (p+1);
     p->type = PA_PACKET_APPENDED;
+    
     return p;
 }
 
-pa_packet* pa_packet_new_dynamic(uint8_t* data, size_t length) {
+pa_packet* pa_packet_new_dynamic(void* data, size_t length) {
     pa_packet *p;
-    assert(data && length);
-    p = pa_xmalloc(sizeof(pa_packet));
+
+    assert(data);
+    assert(length);
+
+    p = pa_xnew(pa_packet, 1);
     p->ref = 1;
     p->length = length;
     p->data = data;
     p->type = PA_PACKET_DYNAMIC;
+    
     return p;
 }
 
 pa_packet* pa_packet_ref(pa_packet *p) {
-    assert(p && p->ref >= 1);
+    assert(p);
+    assert(p->ref >= 1);
+    
     p->ref++;
     return p;
 }
 
 void pa_packet_unref(pa_packet *p) {
-    assert(p && p->ref >= 1);
-    p->ref--;
-
-    if (p->ref == 0) {
+    assert(p);
+    assert(p->ref >= 1);
+    
+    if (--p->ref == 0) {
         if (p->type == PA_PACKET_DYNAMIC)
             pa_xfree(p->data);
         pa_xfree(p);
diff --git a/src/polypcore/packet.h b/src/polypcore/packet.h
index 0ac4748..fbc5823 100644
--- a/src/polypcore/packet.h
+++ b/src/polypcore/packet.h
@@ -33,7 +33,7 @@ typedef struct pa_packet {
 } pa_packet;
 
 pa_packet* pa_packet_new(size_t length);
-pa_packet* pa_packet_new_dynamic(uint8_t* data, size_t length);
+pa_packet* pa_packet_new_dynamic(void* data, size_t length);
 
 pa_packet* pa_packet_ref(pa_packet *p);
 void pa_packet_unref(pa_packet *p);
diff --git a/src/polypcore/protocol-esound.c b/src/polypcore/protocol-esound.c
index a16ac28..5adff57 100644
--- a/src/polypcore/protocol-esound.c
+++ b/src/polypcore/protocol-esound.c
@@ -186,6 +186,7 @@ static void connection_free(struct connection *c) {
 
     if (c->sink_input) {
         pa_sink_input_disconnect(c->sink_input);
+        pa_log("disconnect\n");
         pa_sink_input_unref(c->sink_input);
     }
     
@@ -333,7 +334,15 @@ static int esd_proto_stream_play(struct connection *c, PA_GCC_UNUSED esd_proto_t
     }
 
     l = (size_t) (pa_bytes_per_second(&ss)*PLAYBACK_BUFFER_SECONDS); 
-    c->input_memblockq = pa_memblockq_new(l, 0, pa_frame_size(&ss), l/2, l/PLAYBACK_BUFFER_FRAGMENTS, c->protocol->core->memblock_stat);
+    c->input_memblockq = pa_memblockq_new(
+            0,
+            l,
+            0,
+            pa_frame_size(&ss),
+            (size_t) -1,
+            l/PLAYBACK_BUFFER_FRAGMENTS,
+            NULL,
+            c->protocol->core->memblock_stat);
     pa_iochannel_socket_set_rcvbuf(c->io, l/PLAYBACK_BUFFER_FRAGMENTS*2);
     c->playback.fragment_size = l/10;
 
@@ -405,7 +414,15 @@ static int esd_proto_stream_record(struct connection *c, esd_proto_t request, co
     }
 
     l = (size_t) (pa_bytes_per_second(&ss)*RECORD_BUFFER_SECONDS); 
-    c->output_memblockq = pa_memblockq_new(l, 0, pa_frame_size(&ss), 0, 0, c->protocol->core->memblock_stat);
+    c->output_memblockq = pa_memblockq_new(
+            0,
+            l,
+            0,
+            pa_frame_size(&ss),
+            1,
+            0,
+            NULL,
+            c->protocol->core->memblock_stat);
     pa_iochannel_socket_set_sndbuf(c->io, l/RECORD_BUFFER_FRAGMENTS*2);
     
     c->source_output->owner = c->protocol->module;
@@ -724,8 +741,7 @@ static int do_read(struct connection *c) {
         assert(c->read_data_length < sizeof(c->request));
 
         if ((r = pa_iochannel_read(c->io, ((uint8_t*) &c->request) + c->read_data_length, sizeof(c->request) - c->read_data_length)) <= 0) {
-            if (r != 0)
-                pa_log_warn(__FILE__": read() failed: %s\n", strerror(errno));
+            pa_log_debug(__FILE__": read() failed: %s\n", r < 0 ? strerror(errno) : "EOF");
             return -1;
         }
 
@@ -773,8 +789,7 @@ static int do_read(struct connection *c) {
         assert(c->read_data && c->read_data_length < handler->data_length);
 
         if ((r = pa_iochannel_read(c->io, (uint8_t*) c->read_data + c->read_data_length, handler->data_length - c->read_data_length)) <= 0) {
-            if (r != 0)
-                pa_log_warn(__FILE__": read() failed: %s\n", strerror(errno));
+            pa_log_debug(__FILE__": read() failed: %s\n", r < 0 ? strerror(errno) : "EOF");
             return -1;
         }
 
@@ -794,8 +809,7 @@ static int do_read(struct connection *c) {
         assert(c->scache.memchunk.memblock && c->scache.name && c->scache.memchunk.index < c->scache.memchunk.length);
         
         if ((r = pa_iochannel_read(c->io, (uint8_t*) c->scache.memchunk.memblock->data+c->scache.memchunk.index, c->scache.memchunk.length-c->scache.memchunk.index)) <= 0) {
-            if (r!= 0)
-                pa_log_warn(__FILE__": read() failed: %s\n", strerror(errno));
+            pa_log_debug(__FILE__": read() failed: %s\n", r < 0 ? strerror(errno) : "EOF");
             return -1;
         }
 
@@ -852,13 +866,10 @@ static int do_read(struct connection *c) {
         }
 
         if ((r = pa_iochannel_read(c->io, (uint8_t*) c->playback.current_memblock->data+c->playback.memblock_index, l)) <= 0) {
-            if (r != 0)
-                pa_log(__FILE__": read() failed: %s\n", strerror(errno));
+            pa_log_debug(__FILE__": read() failed: %s\n", r < 0 ? strerror(errno) : "EOF");
             return -1;
         }
         
-/*         pa_log(__FILE__": read %u\n", r);  */
-        
         chunk.memblock = c->playback.current_memblock;
         chunk.index = c->playback.memblock_index;
         chunk.length = r;
@@ -867,7 +878,7 @@ static int do_read(struct connection *c) {
         c->playback.memblock_index += r;
         
         assert(c->input_memblockq);
-        pa_memblockq_push_align(c->input_memblockq, &chunk, 0);
+        pa_memblockq_push_align(c->input_memblockq, &chunk);
         assert(c->sink_input);
         pa_sink_notify(c->sink_input->sink);
     }
@@ -910,6 +921,8 @@ static int do_write(struct connection *c) {
 
         pa_memblockq_drop(c->output_memblockq, &chunk, r);
         pa_memblock_unref(chunk.memblock);
+
+        pa_source_notify(c->source_output->source);
     }
     
     return 0;
@@ -921,21 +934,18 @@ static void do_work(struct connection *c) {
     assert(c->protocol && c->protocol->core && c->protocol->core->mainloop && c->protocol->core->mainloop->defer_enable);
     c->protocol->core->mainloop->defer_enable(c->defer_event, 0);
 
-/*     pa_log("DOWORK %i\n", pa_iochannel_is_hungup(c->io));   */
+    if (c->dead)
+        return;
 
-    if (!c->dead && pa_iochannel_is_readable(c->io))
+    if (pa_iochannel_is_readable(c->io)) {
         if (do_read(c) < 0)
             goto fail;
+    } else if (pa_iochannel_is_hungup(c->io))
+        goto fail;
 
-    if (!c->dead && pa_iochannel_is_writable(c->io))
+    if (pa_iochannel_is_writable(c->io))
         if (do_write(c) < 0)
             goto fail;
-
-    /* In case the line was hungup, make sure to rerun this function
-       as soon as possible, until all data has been read. */
-
-    if (!c->dead && pa_iochannel_is_hungup(c->io))
-        c->protocol->core->mainloop->defer_enable(c->defer_event, 1);
     
     return;
 
@@ -943,15 +953,17 @@ fail:
 
     if (c->state == ESD_STREAMING_DATA && c->sink_input) {
         c->dead = 1;
-        pa_memblockq_prebuf_disable(c->input_memblockq);
 
         pa_iochannel_free(c->io);
         c->io = NULL;
-        
+
+        pa_memblockq_prebuf_disable(c->input_memblockq);
+        pa_sink_notify(c->sink_input->sink);
     } else
         connection_free(c);
 }
 
+
 static void io_callback(pa_iochannel*io, void *userdata) {
     struct connection *c = userdata;
     assert(io && c && c->io == io);
@@ -1024,7 +1036,7 @@ static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk)
     struct connection *c = o->userdata;
     assert(o && c && chunk);
 
-    pa_memblockq_push(c->output_memblockq, chunk, 0);
+    pa_memblockq_push(c->output_memblockq, chunk);
 
     /* do something */
     assert(c->protocol && c->protocol->core && c->protocol->core->mainloop && c->protocol->core->mainloop->defer_enable);
diff --git a/src/polypcore/protocol-native.c b/src/polypcore/protocol-native.c
index 1362fdf..aaa4fc4 100644
--- a/src/polypcore/protocol-native.c
+++ b/src/polypcore/protocol-native.c
@@ -48,6 +48,8 @@
 #include <polypcore/authkey-prop.h>
 #include <polypcore/strlist.h>
 #include <polypcore/props.h>
+#include <polypcore/sample-util.h>
+#include <polypcore/llist.h>
 
 #include "protocol-native.h"
 
@@ -77,6 +79,11 @@ struct playback_stream {
     size_t requested_bytes;
     int drain_request;
     uint32_t drain_tag;
+    uint32_t syncid;
+    int underrun;
+
+    /* Sync group members */
+    PA_LLIST_FIELDS(struct playback_stream);
 };
 
 struct upload_stream {
@@ -153,7 +160,8 @@ static void command_get_server_info(pa_pdispatch *pd, uint32_t command, uint32_t
 static void command_subscribe(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 static void command_set_volume(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 static void command_cork_playback_stream(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
-static void command_flush_or_trigger_playback_stream(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
+static void command_flush_playback_stream(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
+static void command_trigger_or_prebuf_playback_stream(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 static void command_set_default_sink_or_source(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 static void command_set_stream_name(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
 static void command_kill(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata);
@@ -210,9 +218,9 @@ static const pa_pdispatch_callback command_table[PA_COMMAND_MAX] = {
     [PA_COMMAND_SET_SINK_INPUT_VOLUME] = command_set_volume,
     
     [PA_COMMAND_CORK_PLAYBACK_STREAM] = command_cork_playback_stream,
-    [PA_COMMAND_FLUSH_PLAYBACK_STREAM] = command_flush_or_trigger_playback_stream,
-    [PA_COMMAND_TRIGGER_PLAYBACK_STREAM] = command_flush_or_trigger_playback_stream,
-    [PA_COMMAND_PREBUF_PLAYBACK_STREAM] = command_flush_or_trigger_playback_stream,
+    [PA_COMMAND_FLUSH_PLAYBACK_STREAM] = command_flush_playback_stream,
+    [PA_COMMAND_TRIGGER_PLAYBACK_STREAM] = command_trigger_or_prebuf_playback_stream,
+    [PA_COMMAND_PREBUF_PLAYBACK_STREAM] = command_trigger_or_prebuf_playback_stream,
     
     [PA_COMMAND_CORK_RECORD_STREAM] = command_cork_record_stream,
     [PA_COMMAND_FLUSH_RECORD_STREAM] = command_flush_record_stream,
@@ -244,7 +252,7 @@ static struct upload_stream* upload_stream_new(
     struct upload_stream *s;
     assert(c && ss && name && length);
     
-    s = pa_xmalloc(sizeof(struct upload_stream));
+    s = pa_xnew(struct upload_stream, 1);
     s->type = UPLOAD_STREAM;
     s->connection = c;
     s->sample_spec = *ss;
@@ -291,7 +299,7 @@ static struct record_stream* record_stream_new(
     if (!(source_output = pa_source_output_new(source, __FILE__, name, ss, map, -1)))
         return NULL;
 
-    s = pa_xmalloc(sizeof(struct record_stream));
+    s = pa_xnew(struct record_stream, 1);
     s->connection = c;
     s->source_output = source_output;
     s->source_output->push = source_output_push_cb;
@@ -301,7 +309,15 @@ static struct record_stream* record_stream_new(
     s->source_output->owner = c->protocol->module;
     s->source_output->client = c->client;
 
-    s->memblockq = pa_memblockq_new(maxlength, 0, base = pa_frame_size(ss), 0, 0, c->protocol->core->memblock_stat);
+    s->memblockq = pa_memblockq_new(
+            0,
+            maxlength,
+            0,
+            base = pa_frame_size(ss),
+            1,
+            0,
+            NULL,
+            c->protocol->core->memblock_stat);
     assert(s->memblockq);
 
     s->fragment_size = (fragment_size/base)*base;
@@ -332,19 +348,40 @@ static struct playback_stream* playback_stream_new(
     size_t tlength,
     size_t prebuf,
     size_t minreq,
-    pa_cvolume *volume) {
+    pa_cvolume *volume,
+    uint32_t syncid) {
     
-    struct playback_stream *s;
+    struct playback_stream *s, *sync;
     pa_sink_input *sink_input;
+    pa_memblock *silence;
+    uint32_t idx;
+    int64_t start_index;
+    
     assert(c && sink && ss && name && maxlength);
 
+    /* Find syncid group */
+    for (sync = pa_idxset_first(c->output_streams, &idx); sync; sync = pa_idxset_next(c->output_streams, &idx)) {
+        
+        if (sync->type != PLAYBACK_STREAM)
+            continue;
+
+        if (sync->syncid == syncid)
+            break;
+    }
+
+    /* Synced streams must connect to the same sink */
+    if (sync && sync->sink_input->sink != sink)
+        return NULL;
+    
     if (!(sink_input = pa_sink_input_new(sink, __FILE__, name, ss, map, 0, -1)))
         return NULL;
     
-    s = pa_xmalloc(sizeof(struct playback_stream));
+    s = pa_xnew(struct playback_stream, 1);
     s->type = PLAYBACK_STREAM;
     s->connection = c;
+    s->syncid = syncid;
     s->sink_input = sink_input;
+    s->underrun = 1;
     
     s->sink_input->peek = sink_input_peek_cb;
     s->sink_input->drop = sink_input_drop_cb;
@@ -353,24 +390,56 @@ static struct playback_stream* playback_stream_new(
     s->sink_input->userdata = s;
     s->sink_input->owner = c->protocol->module;
     s->sink_input->client = c->client;
-    
-    s->memblockq = pa_memblockq_new(maxlength, tlength, pa_frame_size(ss), prebuf, minreq, c->protocol->core->memblock_stat);
-    assert(s->memblockq);
 
+    if (sync) {
+        /* Sync id found, now find head of list */
+        PA_LLIST_FIND_HEAD(struct playback_stream, sync, &sync);
+
+        /* Prepend ourselves */
+        PA_LLIST_PREPEND(struct playback_stream, sync, s);
+
+        /* Set our start index to the current read index of the other grozp member(s) */
+        assert(sync->next);
+        start_index = pa_memblockq_get_read_index(sync->next->memblockq);
+    } else {
+        /* This ia a new sync group */
+        PA_LLIST_INIT(struct playback_stream, s);
+        start_index = 0;
+    }
+    
+    silence = pa_silence_memblock_new(ss, 0, c->protocol->core->memblock_stat);
+    
+    s->memblockq = pa_memblockq_new(
+            start_index,
+            maxlength,
+            tlength,
+            pa_frame_size(ss),
+            prebuf,
+            minreq,
+            silence,
+            c->protocol->core->memblock_stat);
+
+    pa_memblock_unref(silence);
+    
     s->requested_bytes = 0;
     s->drain_request = 0;
 
     s->sink_input->volume = *volume;
     
     pa_idxset_put(c->output_streams, s, &s->index);
+
     return s;
 }
 
 static void playback_stream_free(struct playback_stream* p) {
+    struct playback_stream *head;
     assert(p && p->connection);
 
     if (p->drain_request)
-        pa_pstream_send_error(p->connection->pstream, p->drain_tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(p->connection->pstream, p->drain_tag, PA_ERR_NOENTITY);
+
+    PA_LLIST_FIND_HEAD(struct playback_stream, p, &head);
+    PA_LLIST_REMOVE(struct playback_stream, head, p);
 
     pa_idxset_remove_by_data(p->connection->output_streams, p, NULL);
     pa_sink_input_disconnect(p->sink_input);
@@ -436,7 +505,7 @@ static void request_bytes(struct playback_stream *s) {
     pa_tagstruct_putu32(t, l);
     pa_pstream_send_tagstruct(s->connection->pstream, t);
 
-/*     pa_log(__FILE__": Requesting %u bytes\n", l); */
+/*     pa_log(__FILE__": Requesting %u bytes\n", l);  */
 }
 
 static void send_memblock(struct connection *c) {
@@ -461,7 +530,7 @@ static void send_memblock(struct connection *c) {
             if (schunk.length > r->fragment_size)
                 schunk.length = r->fragment_size;
 
-            pa_pstream_send_memblock(c->pstream, r->index, 0, &schunk);
+            pa_pstream_send_memblock(c->pstream, r->index, 0, PA_SEEK_RELATIVE, &schunk);
             pa_memblockq_drop(r->memblockq, &chunk, schunk.length);
             pa_memblock_unref(schunk.memblock);
             
@@ -501,9 +570,27 @@ static int sink_input_peek_cb(pa_sink_input *i, pa_memchunk *chunk) {
     assert(i && i->userdata && chunk);
     s = i->userdata;
 
-    if (pa_memblockq_peek(s->memblockq, chunk) < 0)
+    if (pa_memblockq_get_length(s->memblockq) <= 0 && !s->underrun) {
+        pa_tagstruct *t;
+
+        /* Report that we're empty */
+
+        t = pa_tagstruct_new(NULL, 0);
+        pa_tagstruct_putu32(t, PA_COMMAND_UNDERFLOW);
+        pa_tagstruct_putu32(t, (uint32_t) -1); /* tag */
+        pa_tagstruct_putu32(t, s->index);
+        pa_pstream_send_tagstruct(s->connection->pstream, t);
+
+        s->underrun = 1;
+    }
+    
+    if (pa_memblockq_peek(s->memblockq, chunk) < 0) {
+        pa_log(__FILE__": peek: failure\n");   
         return -1;
+    }
 
+/*     pa_log(__FILE__": peek: %u\n", chunk->length);    */
+    
     return 0;
 }
 
@@ -513,6 +600,7 @@ static void sink_input_drop_cb(pa_sink_input *i, const pa_memchunk *chunk, size_
     s = i->userdata;
 
     pa_memblockq_drop(s->memblockq, chunk, length);
+
     request_bytes(s);
 
     if (s->drain_request && !pa_memblockq_is_readable(s->memblockq)) {
@@ -520,7 +608,7 @@ static void sink_input_drop_cb(pa_sink_input *i, const pa_memchunk *chunk, size_
         s->drain_request = 0;
     }
 
-/*     pa_log(__FILE__": after_drop: %u\n", pa_memblockq_get_length(s->memblockq)); */
+/*     pa_log(__FILE__": after_drop: %u %u\n", pa_memblockq_get_length(s->memblockq), pa_memblockq_is_readable(s->memblockq));   */
 }
 
 static void sink_input_kill_cb(pa_sink_input *i) {
@@ -546,7 +634,11 @@ static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk)
     assert(o && o->userdata && chunk);
     s = o->userdata;
     
-    pa_memblockq_push_align(s->memblockq, chunk, 0);
+    if (pa_memblockq_push_align(s->memblockq, chunk) < 0) {
+        pa_log_warn(__FILE__": Failed to push data into output queue.\n");
+        return;
+    } 
+        
     if (!pa_pstream_is_pending(s->connection->pstream))
         send_memblock(s->connection);
 }
@@ -578,7 +670,7 @@ static void command_create_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GC
     struct connection *c = userdata;
     struct playback_stream *s;
     size_t maxlength, tlength, prebuf, minreq;
-    uint32_t sink_index;
+    uint32_t sink_index, syncid;
     const char *name, *sink_name;
     pa_sample_spec ss;
     pa_channel_map map;
@@ -601,6 +693,7 @@ static void command_create_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GC
             PA_TAG_U32, &tlength,
             PA_TAG_U32, &prebuf,
             PA_TAG_U32, &minreq,
+            PA_TAG_U32, &syncid,
             PA_TAG_CVOLUME, &volume,
             PA_TAG_INVALID) < 0 ||
         !pa_tagstruct_eof(t) ||
@@ -610,23 +703,23 @@ static void command_create_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GC
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
-    if (sink_index != (uint32_t) -1)
+    if (sink_index != PA_INVALID_INDEX)
         sink = pa_idxset_get_by_index(c->protocol->core->sinks, sink_index);
     else
         sink = pa_namereg_get(c->protocol->core, sink_name, PA_NAMEREG_SINK, 1);
 
     if (!sink) {
-        pa_log("%s: Can't find a suitable sink.\n", __FILE__);
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_log_warn(__FILE__": Can't find a suitable sink.\n");
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
     
-    if (!(s = playback_stream_new(c, sink, &ss, &map, name, maxlength, tlength, prebuf, minreq, &volume))) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_INVALID);
+    if (!(s = playback_stream_new(c, sink, &ss, &map, name, maxlength, tlength, prebuf, minreq, &volume, syncid))) {
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_INVALID);
         return;
     }
 
@@ -656,14 +749,14 @@ static void command_delete_stream(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t comma
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (command == PA_COMMAND_DELETE_PLAYBACK_STREAM) {
         struct playback_stream *s;
         if (!(s = pa_idxset_get_by_index(c->output_streams, channel)) || (s->type != PLAYBACK_STREAM)) {
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_EXIST);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_EXIST);
             return;
         }
 
@@ -671,7 +764,7 @@ static void command_delete_stream(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t comma
     } else if (command == PA_COMMAND_DELETE_RECORD_STREAM) {
         struct record_stream *s;
         if (!(s = pa_idxset_get_by_index(c->record_streams, channel))) {
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_EXIST);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_EXIST);
             return;
         }
 
@@ -680,7 +773,7 @@ static void command_delete_stream(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t comma
         struct upload_stream *s;
         assert(command == PA_COMMAND_DELETE_UPLOAD_STREAM);
         if (!(s = pa_idxset_get_by_index(c->output_streams, channel)) || (s->type != UPLOAD_STREAM)) {
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_EXIST);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_EXIST);
             return;
         }
 
@@ -717,7 +810,7 @@ static void command_create_record_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -727,12 +820,12 @@ static void command_create_record_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_
         source = pa_namereg_get(c->protocol->core, source_name, PA_NAMEREG_SOURCE, 1);
 
     if (!source) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
     
     if (!(s = record_stream_new(c, source, &ss, &map, name, maxlength, fragment_size))) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_INVALID);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_INVALID);
         return;
     }
 
@@ -758,7 +851,7 @@ static void command_exit(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
     
@@ -782,7 +875,7 @@ static void command_auth(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t
     if (!c->authorized) {
         if (memcmp(c->protocol->auth_cookie, cookie, PA_NATIVE_COOKIE_LENGTH) != 0) {
             pa_log(__FILE__": Denied access to client with invalid authorization key.\n");
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
             return;
         }
         
@@ -826,7 +919,7 @@ static void command_lookup(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command, uin
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -842,7 +935,7 @@ static void command_lookup(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command, uin
     }
 
     if (idx == PA_IDXSET_INVALID)
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
     else {
         pa_tagstruct *reply;
         reply = pa_tagstruct_new(NULL, 0);
@@ -867,12 +960,12 @@ static void command_drain_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(s = pa_idxset_get_by_index(c->output_streams, idx)) || s->type != PLAYBACK_STREAM) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -881,10 +974,10 @@ static void command_drain_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC
     pa_memblockq_prebuf_disable(s->memblockq);
     
     if (!pa_memblockq_is_readable(s->memblockq)) {
-/*         pa_log("immediate drain: %u\n", pa_memblockq_get_length(s->memblockq)); */
+/*         pa_log("immediate drain: %u\n", pa_memblockq_get_length(s->memblockq));  */
         pa_pstream_send_simple_ack(c->pstream, tag);
     } else {
-/*         pa_log("slow drain triggered\n"); */
+/*         pa_log("slow drain triggered\n");  */
         s->drain_request = 1;
         s->drain_tag = tag;
 
@@ -903,7 +996,7 @@ static void command_stat(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -937,12 +1030,12 @@ static void command_get_playback_latency(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(s = pa_idxset_get_by_index(c->output_streams, idx)) || s->type != PLAYBACK_STREAM) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -980,12 +1073,12 @@ static void command_get_record_latency(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UN
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(s = pa_idxset_get_by_index(c->record_streams, idx))) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1026,17 +1119,17 @@ static void command_create_upload_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if ((length % pa_frame_size(&ss)) != 0 || length <= 0 || !*name) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_INVALID);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_INVALID);
         return;
     }
     
     if (!(s = upload_stream_new(c, &ss, &map, name, length))) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_INVALID);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_INVALID);
         return;
     }
     
@@ -1063,12 +1156,12 @@ static void command_finish_upload_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(s = pa_idxset_get_by_index(c->output_streams, channel)) || (s->type != UPLOAD_STREAM)) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_EXIST);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_EXIST);
         return;
     }
 
@@ -1095,7 +1188,7 @@ static void command_play_sample(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED ui
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1105,12 +1198,12 @@ static void command_play_sample(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED ui
         sink = pa_namereg_get(c->protocol->core, sink_name, PA_NAMEREG_SINK, 1);
 
     if (!sink) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
     if (pa_scache_play_item(c->protocol->core, name, sink, &volume) < 0) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1129,12 +1222,12 @@ static void command_remove_sample(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (pa_scache_remove_item(c->protocol->core, name) < 0) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1261,7 +1354,7 @@ static void command_get_info(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command, u
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1292,7 +1385,7 @@ static void command_get_info(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command, u
     }
             
     if (!sink && !source && !client && !module && !si && !so && !sce) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1331,7 +1424,7 @@ static void command_get_info_list(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t comma
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1394,7 +1487,7 @@ static void command_get_server_info(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSE
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1444,7 +1537,7 @@ static void command_subscribe(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1478,7 +1571,7 @@ static void command_set_volume(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command,
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1493,7 +1586,7 @@ static void command_set_volume(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command,
     }
 
     if (!si && !sink) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1509,7 +1602,7 @@ static void command_cork_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_
     struct connection *c = userdata;
     uint32_t idx;
     int b;
-    struct playback_stream *s;
+    struct playback_stream *s, *sync;
     assert(c && t);
 
     if (pa_tagstruct_getu32(t, &idx) < 0 ||
@@ -1520,20 +1613,82 @@ static void command_cork_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(s = pa_idxset_get_by_index(c->output_streams, idx)) || s->type != PLAYBACK_STREAM) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
+    fprintf(stderr, "Corking %i\n", b);
+
     pa_sink_input_cork(s->sink_input, b);
+    pa_memblockq_prebuf_force(s->memblockq);
+
+    /* Do the same for all other members in the sync group */
+    for (sync = s->prev; sync; sync = sync->prev) {
+        pa_sink_input_cork(sync->sink_input, b);
+        pa_memblockq_prebuf_force(sync->memblockq);
+    }
+
+    for (sync = s->next; sync; sync = sync->next) {
+        pa_sink_input_cork(sync->sink_input, b);
+        pa_memblockq_prebuf_force(sync->memblockq);
+    }
+    
+    pa_pstream_send_simple_ack(c->pstream, tag);
+} 
+
+static void command_flush_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {
+    struct connection *c = userdata;
+    uint32_t idx;
+    struct playback_stream *s, *sync;
+    assert(c && t);
+
+    if (pa_tagstruct_getu32(t, &idx) < 0 ||
+        !pa_tagstruct_eof(t)) {
+        protocol_error(c);
+        return;
+    }
+
+    if (!c->authorized) {
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
+        return;
+    }
+
+    if (!(s = pa_idxset_get_by_index(c->output_streams, idx)) || s->type != PLAYBACK_STREAM) {
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
+        return;
+    }
+
+    pa_memblockq_flush(s->memblockq);
+    s->underrun = 0;
+    
+    /* Do the same for all other members in the sync group */
+    for (sync = s->prev; sync; sync = sync->prev) {
+        pa_memblockq_flush(sync->memblockq);
+        sync->underrun = 0;
+    }
+
+    for (sync = s->next; sync; sync = sync->next) {
+        pa_memblockq_flush(sync->memblockq);
+        sync->underrun = 0;
+    }
+    
     pa_pstream_send_simple_ack(c->pstream, tag);
+    pa_sink_notify(s->sink_input->sink);
+    request_bytes(s);
+    
+    for (sync = s->prev; sync; sync = sync->prev)
+        request_bytes(sync);
+
+    for (sync = s->next; sync; sync = sync->next)
+        request_bytes(sync);
 }
 
-static void command_flush_or_trigger_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {
+static void command_trigger_or_prebuf_playback_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {
     struct connection *c = userdata;
     uint32_t idx;
     struct playback_stream *s;
@@ -1546,23 +1701,26 @@ static void command_flush_or_trigger_playback_stream(PA_GCC_UNUSED pa_pdispatch
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(s = pa_idxset_get_by_index(c->output_streams, idx)) || s->type != PLAYBACK_STREAM) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
-    if (command == PA_COMMAND_PREBUF_PLAYBACK_STREAM)
-        pa_memblockq_prebuf_reenable(s->memblockq);
-    else if (command == PA_COMMAND_TRIGGER_PLAYBACK_STREAM)
-        pa_memblockq_prebuf_disable(s->memblockq);
-    else {
-        assert(command == PA_COMMAND_FLUSH_PLAYBACK_STREAM);
-        pa_memblockq_flush(s->memblockq);
-        /*pa_log(__FILE__": flush: %u\n", pa_memblockq_get_length(s->memblockq));*/
+    switch (command) {
+        case PA_COMMAND_PREBUF_PLAYBACK_STREAM:
+            pa_memblockq_prebuf_force(s->memblockq);
+            break;
+            
+        case PA_COMMAND_TRIGGER_PLAYBACK_STREAM:
+            pa_memblockq_prebuf_disable(s->memblockq);
+            break;
+            
+        default:
+            abort();
     }
 
     pa_sink_notify(s->sink_input->sink);
@@ -1585,16 +1743,17 @@ static void command_cork_record_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UN
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(s = pa_idxset_get_by_index(c->record_streams, idx))) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
     pa_source_output_cork(s->source_output, b);
+    pa_memblockq_prebuf_force(s->memblockq);
     pa_pstream_send_simple_ack(c->pstream, tag);
 }
 
@@ -1611,12 +1770,12 @@ static void command_flush_record_stream(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_U
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(s = pa_idxset_get_by_index(c->record_streams, idx))) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1638,7 +1797,7 @@ static void command_set_default_sink_or_source(PA_GCC_UNUSED pa_pdispatch *pd, u
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1660,7 +1819,7 @@ static void command_set_stream_name(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t com
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1668,7 +1827,7 @@ static void command_set_stream_name(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t com
         struct playback_stream *s;
         
         if (!(s = pa_idxset_get_by_index(c->output_streams, idx)) || s->type != PLAYBACK_STREAM) {
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
             return;
         }
 
@@ -1678,7 +1837,7 @@ static void command_set_stream_name(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t com
         struct record_stream *s;
         
         if (!(s = pa_idxset_get_by_index(c->record_streams, idx))) {
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
             return;
         }
 
@@ -1700,7 +1859,7 @@ static void command_kill(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command, uint3
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1708,7 +1867,7 @@ static void command_kill(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command, uint3
         pa_client *client;
         
         if (!(client = pa_idxset_get_by_index(c->protocol->core->clients, idx))) {
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
             return;
         }
 
@@ -1717,7 +1876,7 @@ static void command_kill(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command, uint3
         pa_sink_input *s;
         
         if (!(s = pa_idxset_get_by_index(c->protocol->core->sink_inputs, idx))) {
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
             return;
         }
 
@@ -1728,7 +1887,7 @@ static void command_kill(PA_GCC_UNUSED pa_pdispatch *pd, uint32_t command, uint3
         assert(command == PA_COMMAND_KILL_SOURCE_OUTPUT);
         
         if (!(s = pa_idxset_get_by_index(c->protocol->core->source_outputs, idx))) {
-            pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+            pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
             return;
         }
 
@@ -1753,12 +1912,12 @@ static void command_load_module(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED ui
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(m = pa_module_load(c->protocol->core, name, argument))) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_INITFAILED);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_MODINITFAILED);
         return;
     }
 
@@ -1782,12 +1941,12 @@ static void command_unload_module(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (!(m = pa_idxset_get_by_index(c->protocol->core->modules, idx))) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1813,12 +1972,12 @@ static void command_add_autoload(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSED u
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
     if (pa_autoload_add(c->protocol->core, name, type == 0 ? PA_NAMEREG_SINK : PA_NAMEREG_SOURCE, module, argument, &idx) < 0) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_EXIST);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_EXIST);
         return;
     }
 
@@ -1847,7 +2006,7 @@ static void command_remove_autoload(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSE
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1857,7 +2016,7 @@ static void command_remove_autoload(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNUSE
         r = pa_autoload_remove_by_index(c->protocol->core, idx);
 
     if (r < 0) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1893,7 +2052,7 @@ static void command_get_autoload_info(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNU
     }
 
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1904,7 +2063,7 @@ static void command_get_autoload_info(PA_GCC_UNUSED pa_pdispatch *pd, PA_GCC_UNU
         a = pa_autoload_get_by_index(c->protocol->core, idx);
 
     if (!a) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_NOENTITY);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_NOENTITY);
         return;
     }
 
@@ -1927,7 +2086,7 @@ static void command_get_autoload_info_list(PA_GCC_UNUSED pa_pdispatch *pd, PA_GC
     }
     
     if (!c->authorized) {
-        pa_pstream_send_error(c->pstream, tag, PA_ERROR_ACCESS);
+        pa_pstream_send_error(c->pstream, tag, PA_ERR_ACCESS);
         return;
     }
 
@@ -1958,7 +2117,7 @@ static void pstream_packet_callback(pa_pstream *p, pa_packet *packet, void *user
     }
 }
 
-static void pstream_memblock_callback(pa_pstream *p, uint32_t channel, uint32_t delta, const pa_memchunk *chunk, void *userdata) {
+static void pstream_memblock_callback(pa_pstream *p, uint32_t channel, int64_t offset, pa_seek_mode_t seek, const pa_memchunk *chunk, void *userdata) {
     struct connection *c = userdata;
     struct output_stream *stream;
     assert(p && chunk && userdata);
@@ -1975,13 +2134,30 @@ static void pstream_memblock_callback(pa_pstream *p, uint32_t channel, uint32_t
             ps->requested_bytes = 0;
         else
             ps->requested_bytes -= chunk->length;
-        
-        pa_memblockq_push_align(ps->memblockq, chunk, delta);
-        assert(ps->sink_input);
-/*         pa_log(__FILE__": after_recv: %u\n", pa_memblockq_get_length(p->memblockq)); */
 
+        pa_memblockq_seek(ps->memblockq, offset, seek);
+
+        if (pa_memblockq_push_align(ps->memblockq, chunk) < 0) {
+            pa_tagstruct *t;
+            
+            pa_log_warn(__FILE__": failed to push data into queue\n");
+
+            /* Pushing this block into the queue failed, so we simulate
+             * it by skipping ahead */
+            
+            pa_memblockq_seek(ps->memblockq, chunk->length, PA_SEEK_RELATIVE);
+
+            /* Notify the user */
+            t = pa_tagstruct_new(NULL, 0);
+            pa_tagstruct_putu32(t, PA_COMMAND_OVERFLOW);
+            pa_tagstruct_putu32(t, (uint32_t) -1); /* tag */
+            pa_tagstruct_putu32(t, ps->index);
+            pa_pstream_send_tagstruct(p, t);
+        }
+
+        ps->underrun = 0;
+            
         pa_sink_notify(ps->sink_input->sink);
-/*          pa_log(__FILE__": Recieved %u bytes.\n", chunk->length);  */
 
     } else {
         struct upload_stream *u = (struct upload_stream*) stream;
diff --git a/src/polypcore/protocol-simple.c b/src/polypcore/protocol-simple.c
index 4d3f8e1..fac5423 100644
--- a/src/polypcore/protocol-simple.c
+++ b/src/polypcore/protocol-simple.c
@@ -52,6 +52,8 @@ struct connection {
     pa_memblockq *input_memblockq, *output_memblockq;
     pa_defer_event *defer_event;
 
+    int dead;
+    
     struct {
         pa_memblock *current_memblock;
         size_t memblock_index, fragment_size;
@@ -130,7 +132,7 @@ static int do_read(struct connection *c) {
     }
     
     if ((r = pa_iochannel_read(c->io, (uint8_t*) c->playback.current_memblock->data+c->playback.memblock_index, l)) <= 0) {
-        pa_log(__FILE__": read() failed: %s\n", r == 0 ? "EOF" : strerror(errno));
+        pa_log_debug(__FILE__": read() failed: %s\n", r == 0 ? "EOF" : strerror(errno));
         return -1;
     }
 
@@ -142,7 +144,7 @@ static int do_read(struct connection *c) {
     c->playback.memblock_index += r;
     
     assert(c->input_memblockq);
-    pa_memblockq_push_align(c->input_memblockq, &chunk, 0);
+    pa_memblockq_push_align(c->input_memblockq, &chunk);
     assert(c->sink_input);
     pa_sink_notify(c->sink_input->sink);
     
@@ -170,32 +172,46 @@ static int do_write(struct connection *c) {
     
     pa_memblockq_drop(c->output_memblockq, &chunk, r);
     pa_memblock_unref(chunk.memblock);
+
+    pa_source_notify(c->source_output->source);
     
     return 0;
 }
 
-
 static void do_work(struct connection *c) {
     assert(c);
 
     assert(c->protocol && c->protocol->core && c->protocol->core->mainloop && c->protocol->core->mainloop->defer_enable);
     c->protocol->core->mainloop->defer_enable(c->defer_event, 0);
 
-    if (pa_iochannel_is_writable(c->io))
-        if (do_write(c) < 0)
-            goto fail;
+    if (c->dead)
+        return;
     
-    if (pa_iochannel_is_readable(c->io))
+    if (pa_iochannel_is_readable(c->io)) {
         if (do_read(c) < 0)
             goto fail;
+    } else if (pa_iochannel_is_hungup(c->io))
+        goto fail;
 
-    if (pa_iochannel_is_hungup(c->io))
-        c->protocol->core->mainloop->defer_enable(c->defer_event, 1);
+    if (pa_iochannel_is_writable(c->io)) {
+        if (do_write(c) < 0)
+            goto fail;
+    } 
 
     return;
 
 fail:
-    connection_free(c);
+
+    if (c->sink_input) {
+        c->dead = 1;
+        
+        pa_iochannel_free(c->io);
+        c->io = NULL;
+
+        pa_memblockq_prebuf_disable(c->input_memblockq);
+        pa_sink_notify(c->sink_input->sink);
+    } else
+        connection_free(c);
 }
 
 /*** sink_input callbacks ***/
@@ -205,8 +221,13 @@ static int sink_input_peek_cb(pa_sink_input *i, pa_memchunk *chunk) {
     assert(i && i->userdata && chunk);
     c = i->userdata;
     
-    if (pa_memblockq_peek(c->input_memblockq, chunk) < 0)
+    if (pa_memblockq_peek(c->input_memblockq, chunk) < 0) {
+        
+        if (c->dead)
+            connection_free(c);
+        
         return -1;
+    }
 
     return 0;
 }
@@ -240,7 +261,7 @@ static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk)
     struct connection *c = o->userdata;
     assert(o && c && chunk);
 
-    pa_memblockq_push(c->output_memblockq, chunk, 0);
+    pa_memblockq_push(c->output_memblockq, chunk);
 
     /* do something */
     assert(c->protocol && c->protocol->core && c->protocol->core->mainloop && c->protocol->core->mainloop->defer_enable);
@@ -307,6 +328,7 @@ static void on_connection(pa_socket_server*s, pa_iochannel *io, void *userdata)
     c->playback.current_memblock = NULL;
     c->playback.memblock_index = 0;
     c->playback.fragment_size = 0;
+    c->dead = 0;
     
     pa_iochannel_socket_peer_to_string(io, cname, sizeof(cname));
     c->client = pa_client_new(p->core, __FILE__, cname);
@@ -339,7 +361,15 @@ static void on_connection(pa_socket_server*s, pa_iochannel *io, void *userdata)
         c->sink_input->userdata = c;
 
         l = (size_t) (pa_bytes_per_second(&p->sample_spec)*PLAYBACK_BUFFER_SECONDS);
-        c->input_memblockq = pa_memblockq_new(l, 0, pa_frame_size(&p->sample_spec), l/2, l/PLAYBACK_BUFFER_FRAGMENTS, p->core->memblock_stat);
+        c->input_memblockq = pa_memblockq_new(
+                0,
+                l,
+                0,
+                pa_frame_size(&p->sample_spec),
+                (size_t) -1,
+                l/PLAYBACK_BUFFER_FRAGMENTS,
+                NULL,
+                p->core->memblock_stat);
         assert(c->input_memblockq);
         pa_iochannel_socket_set_rcvbuf(io, l/PLAYBACK_BUFFER_FRAGMENTS*5);
         c->playback.fragment_size = l/10;
@@ -368,7 +398,15 @@ static void on_connection(pa_socket_server*s, pa_iochannel *io, void *userdata)
         c->source_output->userdata = c;
 
         l = (size_t) (pa_bytes_per_second(&p->sample_spec)*RECORD_BUFFER_SECONDS);
-        c->output_memblockq = pa_memblockq_new(l, 0, pa_frame_size(&p->sample_spec), 0, 0, p->core->memblock_stat);
+        c->output_memblockq = pa_memblockq_new(
+                0,
+                l,
+                0,
+                pa_frame_size(&p->sample_spec),
+                1,
+                0,
+                NULL,
+                p->core->memblock_stat);
         pa_iochannel_socket_set_sndbuf(io, l/RECORD_BUFFER_FRAGMENTS*2);
     }
 
diff --git a/src/polypcore/pstream.c b/src/polypcore/pstream.c
index eec93a0..c697dc3 100644
--- a/src/polypcore/pstream.c
+++ b/src/polypcore/pstream.c
@@ -40,12 +40,14 @@
 
 #include "pstream.h"
 
-typedef enum pa_pstream_descriptor_index {
+enum {
     PA_PSTREAM_DESCRIPTOR_LENGTH,
     PA_PSTREAM_DESCRIPTOR_CHANNEL,
-    PA_PSTREAM_DESCRIPTOR_DELTA,
+    PA_PSTREAM_DESCRIPTOR_OFFSET_HI,
+    PA_PSTREAM_DESCRIPTOR_OFFSET_LO,
+    PA_PSTREAM_DESCRIPTOR_SEEK,
     PA_PSTREAM_DESCRIPTOR_MAX
-} pa_pstream_descriptor_index;
+};
 
 typedef uint32_t pa_pstream_descriptor[PA_PSTREAM_DESCRIPTOR_MAX];
 
@@ -58,7 +60,8 @@ struct item_info {
     /* memblock info */
     pa_memchunk chunk;
     uint32_t channel;
-    uint32_t delta;
+    int64_t offset;
+    pa_seek_mode_t seek_mode;
 
     /* packet info */
     pa_packet *packet;
@@ -94,7 +97,7 @@ struct pa_pstream {
     void (*recieve_packet_callback) (pa_pstream *p, pa_packet *packet, void *userdata);
     void *recieve_packet_callback_userdata;
 
-    void (*recieve_memblock_callback) (pa_pstream *p, uint32_t channel, uint32_t delta, const pa_memchunk *chunk, void *userdata);
+    void (*recieve_memblock_callback) (pa_pstream *p, uint32_t channel, int64_t offset, pa_seek_mode_t seek, const pa_memchunk *chunk, void *userdata);
     void *recieve_memblock_callback_userdata;
 
     void (*drain_callback)(pa_pstream *p, void *userdata);
@@ -103,8 +106,8 @@ struct pa_pstream {
     pa_memblock_stat *memblock_stat;
 };
 
-static void do_write(pa_pstream *p);
-static void do_read(pa_pstream *p);
+static int do_write(pa_pstream *p);
+static int do_read(pa_pstream *p);
 
 static void do_something(pa_pstream *p) {
     assert(p);
@@ -112,31 +115,47 @@ static void do_something(pa_pstream *p) {
     p->mainloop->defer_enable(p->defer_event, 0);
 
     pa_pstream_ref(p);
-    
-    if (!p->dead && pa_iochannel_is_readable(p->io))
-        do_read(p);
 
-    if (!p->dead && pa_iochannel_is_writable(p->io))
-        do_write(p);
+    if (!p->dead && pa_iochannel_is_readable(p->io)) {
+        if (do_read(p) < 0)
+            goto fail;
+    } else if (!p->dead && pa_iochannel_is_hungup(p->io))
+        goto fail;
+
+    if (!p->dead && pa_iochannel_is_writable(p->io)) {
+        if (do_write(p) < 0)
+            goto fail;
+    }
+
+    pa_pstream_unref(p);
+    return;
+
+fail:
 
-    /* In case the line was hungup, make sure to rerun this function
-       as soon as possible, until all data has been read. */
+    p->dead = 1;
     
-    if (!p->dead && pa_iochannel_is_hungup(p->io))
-        p->mainloop->defer_enable(p->defer_event, 1);
+    if (p->die_callback)
+        p->die_callback(p, p->die_callback_userdata);
     
     pa_pstream_unref(p);
 }
 
 static void io_callback(pa_iochannel*io, void *userdata) {
     pa_pstream *p = userdata;
-    assert(p && p->io == io);
+    
+    assert(p);
+    assert(p->io == io);
+    
     do_something(p);
 }
 
 static void defer_callback(pa_mainloop_api *m, pa_defer_event *e, void*userdata) {
     pa_pstream *p = userdata;
-    assert(p && p->defer_event == e && p->mainloop == m);
+
+    assert(p);
+    assert(p->defer_event == e);
+    assert(p->mainloop == m);
+    
     do_something(p);
 }
 
@@ -144,7 +163,8 @@ pa_pstream *pa_pstream_new(pa_mainloop_api *m, pa_iochannel *io, pa_memblock_sta
     pa_pstream *p;
     assert(io);
 
-    p = pa_xmalloc(sizeof(pa_pstream));
+    p = pa_xnew(pa_pstream, 1);
+    
     p->ref = 1;
     p->io = io;
     pa_iochannel_set_callback(io, io_callback, p);
@@ -228,7 +248,7 @@ void pa_pstream_send_packet(pa_pstream*p, pa_packet *packet) {
     
 /*     pa_log(__FILE__": push-packet %p\n", packet); */
     
-    i = pa_xmalloc(sizeof(struct item_info));
+    i = pa_xnew(struct item_info, 1);
     i->type = PA_PSTREAM_ITEM_PACKET;
     i->packet = pa_packet_ref(packet);
 
@@ -236,7 +256,7 @@ void pa_pstream_send_packet(pa_pstream*p, pa_packet *packet) {
     p->mainloop->defer_enable(p->defer_event, 1);
 }
 
-void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, uint32_t delta, const pa_memchunk *chunk) {
+void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, int64_t offset, pa_seek_mode_t seek_mode, const pa_memchunk *chunk) {
     struct item_info *i;
     assert(p && channel != (uint32_t) -1 && chunk && p->ref >= 1);
 
@@ -245,11 +265,12 @@ void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, uint32_t delta, co
     
 /*     pa_log(__FILE__": push-memblock %p\n", chunk); */
     
-    i = pa_xmalloc(sizeof(struct item_info));
+    i = pa_xnew(struct item_info, 1);
     i->type = PA_PSTREAM_ITEM_MEMBLOCK;
     i->chunk = *chunk;
     i->channel = channel;
-    i->delta = delta;
+    i->offset = offset;
+    i->seek_mode = seek_mode;
 
     pa_memblock_ref(i->chunk.memblock);
 
@@ -264,7 +285,7 @@ void pa_pstream_set_recieve_packet_callback(pa_pstream *p, void (*callback) (pa_
     p->recieve_packet_callback_userdata = userdata;
 }
 
-void pa_pstream_set_recieve_memblock_callback(pa_pstream *p, void (*callback) (pa_pstream *p, uint32_t channel, uint32_t delta, const pa_memchunk *chunk, void *userdata), void *userdata) {
+void pa_pstream_set_recieve_memblock_callback(pa_pstream *p, void (*callback) (pa_pstream *p, uint32_t channel, int64_t delta, pa_seek_mode_t seek, const pa_memchunk *chunk, void *userdata), void *userdata) {
     assert(p && callback);
 
     p->recieve_memblock_callback = callback;
@@ -286,17 +307,21 @@ static void prepare_next_write_item(pa_pstream *p) {
         p->write.data = p->write.current->packet->data;
         p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = htonl(p->write.current->packet->length);
         p->write.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL] = htonl((uint32_t) -1);
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_DELTA] = 0;
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] = 0;
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO] = 0;
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK] = 0;
     } else {
         assert(p->write.current->type == PA_PSTREAM_ITEM_MEMBLOCK && p->write.current->chunk.memblock);
         p->write.data = (uint8_t*) p->write.current->chunk.memblock->data + p->write.current->chunk.index;
         p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = htonl(p->write.current->chunk.length);
         p->write.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL] = htonl(p->write.current->channel);
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_DELTA] = htonl(p->write.current->delta);
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] = htonl((uint32_t) (((uint64_t) p->write.current->offset) >> 32));
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO] = htonl((uint32_t) ((uint64_t) p->write.current->offset));
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK] = htonl(p->write.current->seek_mode);
     }
 }
 
-static void do_write(pa_pstream *p) {
+static int do_write(pa_pstream *p) {
     void *d;
     size_t l;
     ssize_t r;
@@ -306,7 +331,7 @@ static void do_write(pa_pstream *p) {
         prepare_next_write_item(p);
 
     if (!p->write.current)
-        return;
+        return 0;
 
     assert(p->write.data);
 
@@ -319,7 +344,7 @@ static void do_write(pa_pstream *p) {
     }
 
     if ((r = pa_iochannel_write(p->io, d, l)) < 0)
-        goto die;
+        return -1;
 
     p->write.index += r;
 
@@ -332,15 +357,10 @@ static void do_write(pa_pstream *p) {
             p->drain_callback(p, p->drain_userdata);
     }
 
-    return;
-    
-die:
-    p->dead = 1;
-    if (p->die_callback)
-        p->die_callback(p, p->die_callback_userdata);
+    return 0;
 }
 
-static void do_read(pa_pstream *p) {
+static int do_read(pa_pstream *p) {
     void *d;
     size_t l; 
     ssize_t r;
@@ -356,7 +376,7 @@ static void do_read(pa_pstream *p) {
     }
 
     if ((r = pa_iochannel_read(p->io, d, l)) <= 0)
-        goto die;
+        return -1;
     
     p->read.index += r;
 
@@ -365,8 +385,8 @@ static void do_read(pa_pstream *p) {
 
         /* Frame size too large */
         if (ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]) > FRAME_SIZE_MAX) {
-            pa_log(__FILE__": Frame size too large\n");
-            goto die;
+            pa_log_warn(__FILE__": Frame size too large\n");
+            return -1;
         }
         
         assert(!p->read.packet && !p->read.memblock);
@@ -374,13 +394,16 @@ static void do_read(pa_pstream *p) {
         if (ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL]) == (uint32_t) -1) {
             /* Frame is a packet frame */
             p->read.packet = pa_packet_new(ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]));
-            assert(p->read.packet);
             p->read.data = p->read.packet->data;
         } else {
             /* Frame is a memblock frame */
             p->read.memblock = pa_memblock_new(ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]), p->memblock_stat);
-            assert(p->read.memblock);
             p->read.data = p->read.memblock->data;
+
+            if (ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK]) > PA_SEEK_RELATIVE_END) {
+                pa_log_warn(__FILE__": Invalid seek mode\n");
+                return -1;
+            }
         }
             
     } else if (p->read.index > PA_PSTREAM_DESCRIPTOR_SIZE) {
@@ -396,13 +419,26 @@ static void do_read(pa_pstream *p) {
                 chunk.index = p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE - l;
                 chunk.length = l;
 
-                if (p->recieve_memblock_callback)
+                if (p->recieve_memblock_callback) {
+                    int64_t offset;
+
+                    offset = (int64_t) (
+                            (((uint64_t) ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI])) << 32) |
+                            (((uint64_t) ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO]))));
+                    
                     p->recieve_memblock_callback(
                         p,
                         ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL]),
-                        ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_DELTA]),
+                        offset,
+                        ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK]),
                         &chunk,
                         p->recieve_memblock_callback_userdata);
+                }
+
+                /* Drop seek info for following callbacks */
+                p->read.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK] =
+                    p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] =
+                    p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO] = 0;
             }
         }
 
@@ -427,13 +463,7 @@ static void do_read(pa_pstream *p) {
         }
     }
 
-    return;
-
-die:
-    p->dead = 1;
-    if (p->die_callback)
-        p->die_callback(p, p->die_callback_userdata);
-   
+    return 0;   
 }
 
 void pa_pstream_set_die_callback(pa_pstream *p, void (*callback)(pa_pstream *p, void *userdata), void *userdata) {
@@ -453,20 +483,24 @@ int pa_pstream_is_pending(pa_pstream *p) {
 
 void pa_pstream_set_drain_callback(pa_pstream *p, void (*cb)(pa_pstream *p, void *userdata), void *userdata) {
     assert(p);
+    assert(p->ref >= 1);
 
     p->drain_callback = cb;
     p->drain_userdata = userdata;
 }
 
 void pa_pstream_unref(pa_pstream*p) {
-    assert(p && p->ref >= 1);
+    assert(p);
+    assert(p->ref >= 1);
 
-    if (!(--(p->ref)))
+    if (--p->ref == 0)
         pstream_free(p);
 }
 
 pa_pstream* pa_pstream_ref(pa_pstream*p) {
-    assert(p && p->ref >= 1);
+    assert(p);
+    assert(p->ref >= 1);
+    
     p->ref++;
     return p;
 }
diff --git a/src/polypcore/pstream.h b/src/polypcore/pstream.h
index 10ce58f..741ba9b 100644
--- a/src/polypcore/pstream.h
+++ b/src/polypcore/pstream.h
@@ -25,6 +25,7 @@
 #include <inttypes.h>
 
 #include <polyp/mainloop-api.h>
+#include <polyp/def.h>
 #include <polypcore/packet.h>
 #include <polypcore/memblock.h>
 #include <polypcore/iochannel.h>
@@ -37,10 +38,10 @@ void pa_pstream_unref(pa_pstream*p);
 pa_pstream* pa_pstream_ref(pa_pstream*p);
 
 void pa_pstream_send_packet(pa_pstream*p, pa_packet *packet);
-void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, uint32_t delta, const pa_memchunk *chunk);
+void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, int64_t offset, pa_seek_mode_t seek, const pa_memchunk *chunk);
 
 void pa_pstream_set_recieve_packet_callback(pa_pstream *p, void (*callback) (pa_pstream *p, pa_packet *packet, void *userdata), void *userdata);
-void pa_pstream_set_recieve_memblock_callback(pa_pstream *p, void (*callback) (pa_pstream *p, uint32_t channel, uint32_t delta, const pa_memchunk *chunk, void *userdata), void *userdata);
+void pa_pstream_set_recieve_memblock_callback(pa_pstream *p, void (*callback) (pa_pstream *p, uint32_t channel, int64_t offset, pa_seek_mode_t seek, const pa_memchunk *chunk, void *userdata), void *userdata);
 void pa_pstream_set_drain_callback(pa_pstream *p, void (*cb)(pa_pstream *p, void *userdata), void *userdata);
 
 void pa_pstream_set_die_callback(pa_pstream *p, void (*callback)(pa_pstream *p, void *userdata), void *userdata);
diff --git a/src/polypcore/sample-util.c b/src/polypcore/sample-util.c
index e3bb4aa..e588446 100644
--- a/src/polypcore/sample-util.c
+++ b/src/polypcore/sample-util.c
@@ -34,6 +34,15 @@
 
 #include "sample-util.h"
 
+pa_memblock *pa_silence_memblock_new(const pa_sample_spec *spec, size_t length, pa_memblock_stat*s) {
+    assert(spec);
+
+    if (length == 0)
+        length = pa_bytes_per_second(spec)/10; /* 100 ms */
+
+    return pa_silence_memblock(pa_memblock_new(length, s), spec);
+}
+
 pa_memblock *pa_silence_memblock(pa_memblock* b, const pa_sample_spec *spec) {
     assert(b && b->data && spec);
     pa_silence_memory(b->data, b->length, spec);
diff --git a/src/polypcore/sample-util.h b/src/polypcore/sample-util.h
index 486d284..7ea01a3 100644
--- a/src/polypcore/sample-util.h
+++ b/src/polypcore/sample-util.h
@@ -28,6 +28,7 @@
 #include <polypcore/memchunk.h>
 
 pa_memblock *pa_silence_memblock(pa_memblock* b, const pa_sample_spec *spec);
+pa_memblock *pa_silence_memblock_new(const pa_sample_spec *spec, size_t length, pa_memblock_stat*s);
 void pa_silence_memchunk(pa_memchunk *c, const pa_sample_spec *spec);
 void pa_silence_memory(void *p, size_t length, const pa_sample_spec *spec);
 
diff --git a/src/polypcore/sink.c b/src/polypcore/sink.c
index 9bc478c..1f374f5 100644
--- a/src/polypcore/sink.c
+++ b/src/polypcore/sink.c
@@ -270,6 +270,8 @@ int pa_sink_render(pa_sink*s, size_t length, pa_memchunk *result) {
         result->memblock = pa_memblock_new(length, s->core->memblock_stat);
         assert(result->memblock);
 
+/*          pa_log("mixing %i\n", n);  */
+
         result->length = pa_mix(info, n, result->memblock->data, length, &s->sample_spec, &s->sw_volume);
         result->index = 0;
     }
diff --git a/src/polypcore/sink.h b/src/polypcore/sink.h
index 5fd9784..fa120eb 100644
--- a/src/polypcore/sink.h
+++ b/src/polypcore/sink.h
@@ -34,7 +34,7 @@ typedef struct pa_sink pa_sink;
 #include <polypcore/source.h>
 #include <polypcore/module.h>
 
-#define PA_MAX_INPUTS_PER_SINK 6
+#define PA_MAX_INPUTS_PER_SINK 32
 
 typedef enum pa_sink_state {
     PA_SINK_RUNNING,
diff --git a/src/tests/memblockq-test.c b/src/tests/memblockq-test.c
new file mode 100644
index 0000000..b01084d
--- /dev/null
+++ b/src/tests/memblockq-test.c
@@ -0,0 +1,147 @@
+/* $Id$ */
+
+/***
+  This file is part of polypaudio.
+ 
+  polypaudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+ 
+  polypaudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public License
+  along with polypaudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <assert.h>
+#include <stdio.h>
+
+#include <polypcore/memblockq.h>
+#include <polypcore/log.h>
+
+int main(int argc, char *argv[]) {
+    int ret;
+    pa_memblockq *bq;
+    pa_memchunk chunk1, chunk2, chunk3, chunk4;
+    pa_memblock *silence;
+
+    pa_log_set_maximal_level(PA_LOG_DEBUG);
+    
+    silence = pa_memblock_new_fixed("__", 2, 1, NULL);
+    assert(silence);
+
+    bq = pa_memblockq_new(0, 40, 10, 2, 4, 4, silence, NULL);
+    assert(bq);
+
+    chunk1.memblock = pa_memblock_new_fixed("AA", 2, 1, NULL);
+    chunk1.index = 0;
+    chunk1.length = 2;
+    assert(chunk1.memblock);
+    
+    chunk2.memblock = pa_memblock_new_fixed("TTBB", 4, 1, NULL);
+    chunk2.index = 2;
+    chunk2.length = 2;
+    assert(chunk2.memblock);
+
+    chunk3.memblock = pa_memblock_new_fixed("ZZZZ", 4, 1, NULL);
+    chunk3.index = 0;
+    chunk3.length = 4;
+    assert(chunk3.memblock);
+
+    chunk4.memblock = pa_memblock_new_fixed("KKKKKKKK", 8, 1, NULL);
+    chunk4.index = 0;
+    chunk4.length = 8;
+    assert(chunk4.memblock);
+
+    ret = pa_memblockq_push(bq, &chunk1);
+    assert(ret == 0);
+    
+    ret = pa_memblockq_push(bq, &chunk1);
+    assert(ret == 0);
+    
+    ret = pa_memblockq_push(bq, &chunk2);
+    assert(ret == 0);
+    
+    ret = pa_memblockq_push(bq, &chunk2);
+    assert(ret == 0);
+
+    pa_memblockq_seek(bq, -6, 0);
+    ret = pa_memblockq_push(bq, &chunk3);
+    assert(ret == 0);
+
+    pa_memblockq_seek(bq, -2, 0);
+    ret = pa_memblockq_push(bq, &chunk3);
+    assert(ret == 0);
+
+    pa_memblockq_seek(bq, -10, 0);
+    ret = pa_memblockq_push(bq, &chunk4);
+    assert(ret == 0);
+
+    pa_memblockq_seek(bq, 10, 0);
+
+    ret = pa_memblockq_push(bq, &chunk1);
+    assert(ret == 0);
+
+    pa_memblockq_seek(bq, -6, 0);
+    ret = pa_memblockq_push(bq, &chunk2);
+    assert(ret == 0);
+
+    /* Test splitting */
+    pa_memblockq_seek(bq, -12, 0);
+    ret = pa_memblockq_push(bq, &chunk1);
+    assert(ret == 0);
+
+    pa_memblockq_seek(bq, 20, 0);
+
+    /* Test merging */
+    ret = pa_memblockq_push(bq, &chunk3);
+    assert(ret == 0);
+    pa_memblockq_seek(bq, -2, 0);
+
+    chunk3.index += 2;
+    chunk3.length -= 2;
+    
+    ret = pa_memblockq_push(bq, &chunk3);
+    assert(ret == 0);
+    
+    printf(">");
+
+    pa_memblockq_shorten(bq, 6);
+    
+    for (;;) {
+        pa_memchunk out;
+        char *e;
+        size_t n;
+        
+        if (pa_memblockq_peek(bq, &out) < 0)
+            break;
+
+        for (e = (char*) out.memblock->data + out.index, n = 0; n < out.length; n++)
+            printf("%c", *e);
+
+        pa_memblock_unref(out.memblock);
+        pa_memblockq_drop(bq, &out, out.length);
+    }
+    
+    printf("<\n");
+    
+    pa_memblockq_free(bq);
+    pa_memblock_unref(silence);
+    pa_memblock_unref(chunk1.memblock);
+    pa_memblock_unref(chunk2.memblock);
+    pa_memblock_unref(chunk3.memblock);
+    pa_memblock_unref(chunk4.memblock);
+    
+    return 0;
+}
diff --git a/src/tests/sync-playback.c b/src/tests/sync-playback.c
new file mode 100644
index 0000000..5df790c
--- /dev/null
+++ b/src/tests/sync-playback.c
@@ -0,0 +1,192 @@
+/* $Id$ */
+
+/***
+  This file is part of polypaudio.
+ 
+  polypaudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+ 
+  polypaudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public License
+  along with polypaudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <math.h>
+
+#include <polyp/polypaudio.h>
+#include <polyp/mainloop.h>
+
+#define NSTREAMS 4
+#define SINE_HZ 440
+#define SAMPLE_HZ 8000
+
+static pa_context *context = NULL;
+static pa_stream *streams[NSTREAMS];
+static pa_mainloop_api *mainloop_api = NULL;
+
+static float data[SAMPLE_HZ]; /* one second space */
+
+static int n_streams_ready = 0;
+
+static const pa_sample_spec sample_spec = {
+    .format = PA_SAMPLE_FLOAT32,
+    .rate = SAMPLE_HZ,
+    .channels = 1
+};
+
+static const pa_buffer_attr buffer_attr = {
+    .maxlength = SAMPLE_HZ*sizeof(float)*NSTREAMS, /* exactly space for the entire play time */
+    .tlength = 0,
+    .prebuf = 0, /* Setting prebuf to 0 guarantees us the the streams will run synchronously, no matter what */
+    .minreq = 0
+};
+
+static void nop_free_cb(void *p) {}
+
+static void underflow_cb(struct pa_stream *s, void *userdata) {
+    int i = (int) userdata;
+
+    fprintf(stderr, "Stream %i finished\n", i);
+    
+    if (++n_streams_ready >= 2*NSTREAMS) {
+        fprintf(stderr, "We're done\n");
+        mainloop_api->quit(mainloop_api, 0);
+    }
+}
+
+/* This routine is called whenever the stream state changes */
+static void stream_state_callback(pa_stream *s, void *userdata) {
+    assert(s);
+
+    switch (pa_stream_get_state(s)) {
+        case PA_STREAM_UNCONNECTED:
+        case PA_STREAM_CREATING:
+        case PA_STREAM_TERMINATED:
+            break;
+
+        case PA_STREAM_READY: {
+
+            int r, i = (int) userdata;
+
+            fprintf(stderr, "Writing data to stream %i.\n", i);
+            
+            r = pa_stream_write(s, data, sizeof(data), nop_free_cb, sizeof(data) * i, PA_SEEK_ABSOLUTE);
+            assert(r == 0);
+
+            /* Be notified when this stream is drained */
+            pa_stream_set_underflow_callback(s, underflow_cb, userdata);
+            
+            /* All streams have been set up, let's go! */
+            if (++n_streams_ready >= NSTREAMS) {
+                fprintf(stderr, "Uncorking\n");
+                pa_operation_unref(pa_stream_cork(s, 0, NULL, NULL));
+            }
+           
+            break;
+        }
+
+        default:
+        case PA_STREAM_FAILED:
+            fprintf(stderr, "Stream error: %s\n", pa_strerror(pa_context_errno(pa_stream_get_context(s))));
+            abort();
+    }
+}
+
+/* This is called whenever the context status changes */
+static void context_state_callback(pa_context *c, void *userdata) {
+    assert(c);
+
+    switch (pa_context_get_state(c)) {
+        case PA_CONTEXT_CONNECTING:
+        case PA_CONTEXT_AUTHORIZING:
+        case PA_CONTEXT_SETTING_NAME:
+            break;
+        
+        case PA_CONTEXT_READY: {
+
+            int i;
+            fprintf(stderr, "Connection established.\n");
+
+            for (i = 0; i < NSTREAMS; i++) {
+                char name[64];
+
+                fprintf(stderr, "Creating stream %i\n", i);
+                
+                snprintf(name, sizeof(name), "stream #%i", i);
+            
+                streams[i] = pa_stream_new(c, name, &sample_spec, NULL);
+                assert(streams[i]);
+                pa_stream_set_state_callback(streams[i], stream_state_callback, (void*) i);
+                pa_stream_connect_playback(streams[i], NULL, &buffer_attr, PA_STREAM_START_CORKED, NULL, i == 0 ? NULL : streams[0]);
+            }
+                
+            break;
+        }
+            
+        case PA_CONTEXT_TERMINATED:
+            mainloop_api->quit(mainloop_api, 0);
+            break;
+
+        case PA_CONTEXT_FAILED:
+        default:
+            fprintf(stderr, "Context error: %s\n", pa_strerror(pa_context_errno(c)));
+            abort();
+    }
+}
+
+int main(int argc, char *argv[]) {
+    pa_mainloop* m = NULL;
+    int i, ret = 0;
+
+    for (i = 0; i < SAMPLE_HZ; i++)
+        data[i] = (float) sin(((double) i/SAMPLE_HZ)*2*M_PI*SINE_HZ)/2;
+
+    for (i = 0; i < NSTREAMS; i++)
+        streams[i] = NULL;
+    
+    /* Set up a new main loop */
+    m = pa_mainloop_new();
+    assert(m);
+
+    mainloop_api = pa_mainloop_get_api(m);
+
+    context = pa_context_new(mainloop_api, argv[0]);
+    assert(context);
+
+    pa_context_set_state_callback(context, context_state_callback, NULL);
+
+    pa_context_connect(context, NULL, 1, NULL);
+
+    if (pa_mainloop_run(m, &ret) < 0)
+        fprintf(stderr, "pa_mainloop_run() failed.\n");
+
+    pa_context_unref(context);
+
+    for (i = 0; i < NSTREAMS; i++)
+        if (streams[i])
+            pa_stream_unref(streams[i]);
+
+    pa_mainloop_free(m);
+    
+    return ret;
+}
diff --git a/src/utils/pacat.c b/src/utils/pacat.c
index a3c3f2c..4e126c8 100644
--- a/src/utils/pacat.c
+++ b/src/utils/pacat.c
@@ -80,7 +80,7 @@ static void do_stream_write(size_t length) {
     if (l > buffer_length)
         l = buffer_length;
     
-    pa_stream_write(stream, (uint8_t*) buffer + buffer_index, l, NULL, 0);
+    pa_stream_write(stream, (uint8_t*) buffer + buffer_index, l, NULL, 0, PA_SEEK_RELATIVE);
     buffer_length -= l;
     buffer_index += l;
     
@@ -106,8 +106,8 @@ static void stream_write_callback(pa_stream *s, size_t length, void *userdata) {
 
 /* This is called whenever new data may is available */
 static void stream_read_callback(pa_stream *s, size_t length, void *userdata) {
+    const void *data;
     assert(s && length);
-    void *data;
 
     if (stdio_event)
         mainloop_api->io_enable(stdio_event, PA_IO_EVENT_OUTPUT);
@@ -175,7 +175,7 @@ static void context_state_callback(pa_context *c, void *userdata) {
 
             if (mode == PLAYBACK) {
                 pa_cvolume cv;
-                pa_stream_connect_playback(stream, device, NULL, 0, pa_cvolume_set(&cv, PA_CHANNELS_MAX, volume));
+                pa_stream_connect_playback(stream, device, NULL, 0, pa_cvolume_set(&cv, PA_CHANNELS_MAX, volume), NULL);
             } else
                 pa_stream_connect_record(stream, device, NULL, 0);
                 
diff --git a/src/utils/pactl.c b/src/utils/pactl.c
index 4c22c92..e3305f0 100644
--- a/src/utils/pactl.c
+++ b/src/utils/pactl.c
@@ -515,7 +515,7 @@ static void stream_write_callback(pa_stream *s, size_t length, void *userdata) {
         quit(1);
     }
     
-    pa_stream_write(s, d, length, free, 0);
+    pa_stream_write(s, d, length, free, 0, PA_SEEK_RELATIVE);
 
     sample_length -= length;
 
diff --git a/src/utils/paplay.c b/src/utils/paplay.c
index 9f73b83..5f985ee 100644
--- a/src/utils/paplay.c
+++ b/src/utils/paplay.c
@@ -113,7 +113,7 @@ static void stream_write_callback(pa_stream *s, size_t length, void *userdata) {
     f = readf_function(sndfile, data, n);
 
     if (f > 0)
-        pa_stream_write(s, data, f*k, free, 0);
+        pa_stream_write(s, data, f*k, free, 0, PA_SEEK_RELATIVE);
 
     if (f < n) {
         sf_close(sndfile);
@@ -166,7 +166,7 @@ static void context_state_callback(pa_context *c, void *userdata) {
 
             pa_stream_set_state_callback(stream, stream_state_callback, NULL);
             pa_stream_set_write_callback(stream, stream_write_callback, NULL);
-            pa_stream_connect_playback(stream, device, NULL, 0, pa_cvolume_set(&cv, PA_CHANNELS_MAX, volume));
+            pa_stream_connect_playback(stream, device, NULL, 0, pa_cvolume_set(&cv, sample_spec.channels, volume), NULL);
                 
             break;
         }